A couple of observations about some Pentecost icons.
First, the empty seat at the top is the Empty or Teaching Seat. This Seat represents the place where Christ sits, not physically present but present now through the Holy Spirit and continuing to instruct the church.
Second, Paul is included among the apostles sitting at the top right across from Peter on the top left. Frequently icons conflate or stack time, stacking past, present and future events on top of each other.
Third, who is that old king at the bottom of the icon?
That is Kosmos (or Cosmos) representing the entire world, not creation but the peoples of the world. Kosmos holds in his hands scrolls of apostolic teachings symbolizing that with the outpouring of the Holy Spirit and the commissioning of the church the teachings of Jesus are spreading throughout the whole world. And having received this teaching Kosmos--the peoples of the world--are now emerging out of darkness.
I hope you have a blessed Pentecost.
Happy Birthday Church!