I have done sooooo much research on the mosaics of the Cappella and have not found the third mosaic – shown on the left above – anywhere. Anywhere at all. I’m knackered and am giving up on him.
So… I just decided it is Aaron Abrams. Yep. That’s what I decided. It is St. Aaron of Abrams. It is an ironic inside joke of some sort. That’s my story and I’m sticking to it!!
(In my search for this guy, I found an amazing site that lets you look at all the mosaics individually andhas a magnifying glass to inspect them further. Go here and use the search phrase “Cappella Palatina.”)