As for identification, my first reaction was Prince William because of the hair and he often dresses that way. Seems slightly heavy for him. As to family similarity, could be Prince Edward, and he's been to HK several times, most recently this June. Definitely not Prince Andrew.
But, don’t mind me, I’m just lurking along.
I had the very same thought of William the instant I saw the picture, then had the same thought of the man being security with him, then decided against that as he looked too small to be a threat ala Jackie Chan, and the picture was wide enough not to shown security in the original shot. But, yes, not just the hair, but the slouch, too.