The locations of Christian imagery often appear as only shadows of their former glory among the walls of the Hagia Sophia. I found a few silhouettes (that were nearly upsetting) up in the gallery where it was evident that the walls were lined with the Eastern Orthodox cross figurines.
Other evidence of the cross figure was a silhouette on the inner-side of the marble wall leading to the area for council members only. This is the popular image of the cross standing on the orb used by Constantine. It is sad that we must leave it to our imaginations alone as to what materials these images were made of and if or how they were adorned.
If the Islamic faith forbids such images, then I am still baffled as to why any Christian images in the Hagia Sophia exist today at all. The images of the Virgin Mary and Gabriel are very vivid and well-preserved so I don’t understand why the sultans ordered them to just be covered with plaster instead of being destroyed. It is believed that the sultan who had these images covered was doing so to prevent any more vandalism and/or to preserve these images as historical artifacts. I have a difficult time understanding this reasoning based on the iconoclastic beliefs and the measures already taken to convert the Hagia Sophia into a mosque.