Beneath the lunettes are the four panels of the upper register. The two outer panels of the middle register show the Annunciation to Mary, with the Archangel Gabriel on the left and the Virgin Mary on the right. Both are dressed in white robes, and occupy what appear to be the opposite ends of the same room. Gabriel and Mary's panels are separated by two much narrower images showing unoccupied domestic interior scenes. The back wall in the left-hand image has a window opening onto a view of street and city square, while that in the right-hand image has a niche. Some art historians have attempted to associate the street with an actual location in Ghent, but it is generally accepted that it is not modeled on any specific place. The sparseness of these narrow panels seem anomalous in the overall context of the altarpiece; a number of art historians have suggested that they were compromises worked out by Jan as he struggled to accommodate his design within the original framework set out by Hubert.