You're absolutely correct, Imal. Having spent some time in the ME, I can say that muslim machismo rivals that seen in Central and South American countries. Muslim countries are very patriarchal, so to have a woman dominating you is a punishment worse than death.
I haven't spent much time on this whole prisoner-humiliation thing until today, when I took some time to study the pictures. The first thing that jumped out at me was the point I just discussed--this is a very humiliating thing for a muslim man. Secondly, I had to wonder just how these pictures were (a) allowed to be taken, and (b) how they were released since it was known that they were taken (smile for the camera!). Like you, I suspected that this might be a setup, especially when I saw that frail girl (Lindy?) holding a strapping Iraqi man on a leash. We can't bury them in pigskins, so we went for the next best thing. I think your theory has merit.