The first Sunday after Eastern is called the Sunday of Thomas.
In the icon, Christ shows himself to Thomas. Christ, the dominant figure at the center, initiates the activity in the icons as he bends toward Thomas and shows him his side. Thomas is called to see and believe. The remaining Apostles stand as witnesses to the Risen Lord. This Event takes place in the upper room where the Disciples gathered, and the closed doors witness to Christ’s entering even though the doors were locked. This icon is a witness of the Resurrection. 1
1 Come Bless The Lord, GOD WITH US, Catechetical Series, 1976.