The wings of the altar-piece can be closed to reveal a painting of the Annunciation to the Virgin. Although the scene is divided among two specially framed panels, it creates the impression of being one single image. The richly patterned gold curtain that stretches from one end of the scene to the other and the fact that the ceiling and the stone floor are both painted in perspective creates a very uniform, naturalistic space. Although the greeting of the angel entering the room through the door on the right-hand side seems entirely realistic and spontaneous, the understated colours used for the figures, the gentleness of the Virgin, and her golden nimbus create the impression of timelessness.