Taking pictures of the food, seats and cabin crew has nothing to do with 'security issues'.

CX is not as paranoid as US carriers. In fact, I heard the Captain sort of sigh once when he made his announcement when welcoming us aboard the flight that CX 'would appreciate' if no one congregates at the galley or cockpit area as 'we are entering US airspace'.... you don't hear this sort of announcement anywhere else they fly. None of this 'our flight attendants are here primarily for your safety issues... etc etc'.

It's more like :"Our Inflight Service Manager, Catherine, is here with her team to ensure you have a comfortable and enjoyable flight"