The difference between what the Iraqis showed and what was shown on TV of the Iraqis is that the folks from the 507th were televised by the governemtn of Iraq. The Iraqi prisoners of war were shown by various TV networks, not the US or UK governments.

The first case is considered to be a humiliation of the prisoners and to be using them for propoganda, both of which are forbidden by the Geneva Accords. The Accords recognize that private citizens or corporations might also photograph or televise POWs, but the Accords can only apply to governments.