Fifty days after Pascha we celebrate the Great Feast of Pentecost when the Holy Spirit came down on the apostles in the form of tongues of fire; ‘Pentecost’ is a Greek word meaning ‘fiftieth’. On Pentecost we celebrate not only the descent of the Holy Spirit but also the whole mystery of the Trinity.
The icon of Pentecost is not just a painting of the events in the room where the apostles received the Holy Spirit. We can see this clearly by the fact that St. Paul is shown on the icon; he was not even a Christian at the time of Pentecost. St. Paul is painted to demonstrate that the Holy Spirit came down on the whole Church and not just on the twelve apostles.
The twelve apostles sit on a horseshoe shaped bench indicating the unity and order in the Church (cf. 1 Cor. 14:40). This order is further demonstrated by the fact that the apostles are portrayed sitting calmly occupying places in accordance with their importance and age. Each, however, is painted in a different posture to signify the different gifts of the Holy Spirit that St. Paul describes:
There are diversities of gifts, but the same Spirit. There are differences of ministries, but the same Lord. And there are diversities of activities, but it is the same God who works all in all. But the manifestation of the Spirit is given to each one for the profit of all: for to one is given the word of wisdom through the Spirit, to another the word of knowledge through the same Spirit, to another faith by the same Spirit, to another gifts of healings by the same Spirit, to another the working of miracles, to another prophecy, to another discerning of spirits, to another different kinds of tongues, to another the interpretation of tongues. But one and the same Spirit works all these things, distributing to each one individually as He wills (1. Cor. 12: 4-11).
The group of the apostles are painted in inverse perspective (the figures at the back of the icon are larger than those at the front). This is to show that the Church is not an ordinary organisation, but a divine-human organism: the Body of Christ.
The top space on the bench is left unoccupied symbolizing Christ the Head of the Church which is His Body (cf. Col. 1:18). The Church, however, existed before Pentecost because the angels are members of the Church. This spiritual church became the physical Body of Christ when Christ took flesh of the Virgin Mary and became man. This is the reason why the Incarnation (when the Son of God put on flesh) is mentioned so often in the hymns of Pentecost.
From the 17th century, particularly in Russian icons, the Mother of God began to be shown in this seat. In doing so, iconographers were probably trying to emphasize that the Mother of God was present at Pentecost (cf. Acts 1:14), but there is also a possibility that this practice started due to western influence.
The semicircle at the top of the icon represents the vault of heavens and the twelve rays coming from it represent the tongues of fire descending on the apostles. In some icons these rays reach down right on to the apostles’ heads. In others, a small tongue of fire is drawn within the halo on each apostle and the rays are cut short. Western religious pictures (right) of Pentecost usually depict flames or fire but this is not found in Orthodoxy.
At the time of Pentecost some of the people present thought that the apostles were drunk when they heard them speaking in foreign languages (cf. Acts 2:13). We should mention briefly that the Protestant charismatic practice of ‘speaking in tongues’ has nothing to do with Pentecost. These Protestants that utter nonsense words, grunts or animal noises believe that they are ‘speaking in tongues’ but they are not! ‘Speaking in tongues’ means speaking foreign languages. This strange behaviour is not actually new at all – sects in the early centuries of Christianity did it too. It is either caused by mass hysteria, fakery, or some form of demonic activity. It has nothing to do with the Holy Spirit.
In ancient icons the watchers in the room were represented as people of different races dressed in their traditional national costume. Over them was written: ‘Peoples, Races and Tongues’ (cf. Rev. 7:9). In newer Orthodox Pentecost icons, this group of people are represented by the figure of the king at the bottom of the icon. The inscription above the man is ‘Cosmos’ which is a Greek word meaning ‘world’ or ‘universe’. In the sense that it is used in the Pentecost icon, ‘cosmos’ means ‘peoples of the world’. The black background behind this figure signifies the darkness of the world before the coming of the Holy Spirit. The figure is painted as an old man to signify that he had been made old by the sin of Adam. The crown represents sin which had ruled over the world, and the cloth containing the twelve scrolls represents the teaching of the apostles.
A few artists place the Mother of God at the bottom of the icon instead of the King, but this is not Orthodox. On the most basic level, by replacing the symbol of the unenlightened nations with the Mother of God, these artists are intimating that the Theotokos who is ‘full of grace’ (Luke 1:28) is on the same level as unbaptized and unconverted idolaters.
Iconography has changed in style over the centuries. For example, although most iconographers today paint in the Byzantine style, this style was used very rarely in 19th century Greece and Russia. The idea of ‘correct’ iconography is therefore a myth because there are so many variations. St. Nicedemos the Hagiorite, for example, states that some older Pentecost icons had the Prophet Joel instead of the King Cosmos. This is because the Prophet Joel foretold the coming of the Holy Spirit at Pentecost when he prophesied: ‘I will pour out my spirit upon all flesh’. This prophecy of Joel is read on Pentecost Vespers on Saturday evening.
Having said that, placing the Mother of God at the bottom of the icon is an innovation done to illustrate a modern theory rather than Scripture. Artists that do this have undoubtedly been influenced by the teachings of Sergius Bulgakov who believed that the Mother of God received spiritual rebirth at Pentecost. According to Bulgakov, ‘with Pentecost, the work of the Divine Motherhood can be considered completed.’ 
Bulgakov believed in Divine Motherhood because he also believed in Sophia. The ideas of Bulgakov are confused and confusing, but basically he believed in a fourth person of the Holy Trinity which he called ‘Wisdom’ or ‘Sophia’ that supports and animates the universe and is a meditatress between God and creation. He also believed that the Mother of God was the ‘full revelation of Sofia in a human being’  the ‘personal incarnation of the Church’ and the ‘focus of the whole creaturely world’. 
Orthodox theologians such as Saint Seraphim of Sofia and Saint John of Shanghai criticized Bulgakov for his views and asserted that he was in danger of confusing the Holy Spirit with the Mother of God.  Bulgakov was condemned by both parts of the Russian Church for his teaching on Sophia. Of course, there is no basis anywhere in the services of Pentecost for these heretical ideas.
In this modernist icon the Mother of God holds twelve ‘seeds of the Word’ instead of twelve scrolls. According to the artists, the Mother of God transforms the teachings of the apostles represented by the scrolls into the seeds of faith. Can there be any doubt that the Mother of God in this icon represents Sophia?
The Orthodox Church honours the Mother of God in the proper fashion and never confuses her with the Holy Spirit. It was the Holy Spirit, not an imaginary ’Sophia’ that transformed the apostles and enabled them to convert the unbelieving nations. This is why we chant the following Prokeimenon on Pentecost and on every feast of the apostles: ‘Their sound hath gone forth into all the earth, and their words unto the ends of the world.’
The traditional Orthodox Pentecost icon illustrates the manifestation of the Church to the world and the coming of the Divine Spirit that united those who were formerly divided and made them wise with the knowledge of the Trinity.
Let us not forget that the grace of the Holy Spirit poured out on the apostles at Pentecost is still being poured out on us today. This Holy Spirit is the Spirit of truth that fills all things and is everywhere present, a treasury of good things, the Giver of life and, as Saint Seraphim of Sofia explains, our Comforter:
The Grace of the Holy Spirit in its various and wondrous manifestations gives birth within us to the bliss of the Kingdom of God. For this reason, it is our true Christian joy. Our Lord and Saviour did not call the Holy Spirit ‘The Comforter’ in vain. This very name informs us that only through the Holy Spirit are we able to have real consolation in all of our misfortunes and through His Grace to receive while still here (on earth) access to all of the joys of the Kingdom of God. 
 S. Bulgakov The Burning Bush (Grand Rapids: Wm. B. Erdmans Publising Co. 2009) p.69
 Ibid p.69
 The Burning Bush p.101
 Schemanun Seraphima (trans.) Saint Seraphim of Sofia (Etna: CTOS, 2008) p. 39
 Saint Seraphim of Sofia p.163