Also the intended punishment is possibly to protect the guilty idiots involved. Mr Taliban is not going to let this go. Post Afghan they could possibly seek revenge on said idiot in photo or even worse, his family.
Remember the enemy can travel too and they are not all stupid!. I for one would now forever be looking over my shoulder if it were me in the photo. You just dont do it. It can also be used in propaganda tactics.
Rule number one just dont expose yourself to the unnecessary. Another big threat to the services is social media.