The arch of the Bema depicts the scene of the Annunciation. The archangel Gabriel is depicted on the left half, with the Virgin Mary on the right half. At the top of the arch, the hand of God witnesses the scene. The angel seems to be moving, leaning towards Mary who, in turn, wrapped in a tunic, holds a mass of red wool in her left hand. Her right hand is raised in front of her chest. There is a cup on her lap, with a ball of wool inside.