FYI, if you are military traveling on orders, you are exempt from selectee screening. Have your orders and mil id and present them to the ticket agent. Of course if you set off the metal detector or they find something on the X-ray or whatever they are fair game.
It is not illegal to take photos at the check-point as long as it does not appear that you are casing the place such as photographing equipment, screeners, procedures, etc. I didn't get to see the photo taken.
Most of the military (except the Navy and maybe the CG)travel in BDU's, or civvies nowadays.
When she said that she was screening you because of what she was wearing maybe she meant it was because your uniform had a lot of metal, brass buttons, metals, ribbons, badges, shanks in your shoes etc. I don't know. That would be bad press to single out military.
Hope this helps,
Del the evil screener.