They are very definitely banned.Why not ban girlie magazines and all booze in general -- they can be smuggled as contraband too.
Afghanistan is NOT Iraq. They could do and have things in Iraq that are not remotely allowed in Afghanistan. There is also a high amount of professionalism expected of the officers and this does not fit that standard.
If you do the photos, wait until he's home to give them to him. When he's caught with them (and there's no way my husband could have kept something like this secret, even at his rank), the incident will make it onto his next OER. When he's putting in for the next bump in rank, all of his OERs will get reviewed. He will not be high on the list. If I were you, I'd be honest with the wife about this and remind her that she can have a lot of responsibility for how his career goes, too.
The uniform is not the problem at all - just his location and the rules they have for troops over there.