Hmm... Oh, I dunno. It’s just part of the whole entertaining-the-outta-towners that happens pretty much everywhere. I’m pretty sure several Presidents have been given a Mao jacket or shirt at one time or another. Doesn’t bother me much.
Though... he looks more natural in it than any of the others have.
I seem to recall an economic summit meeting that took place in Indonesia some years back. All the heads-of-state & their finance ministers were attired in long shirts similar to the ones in Barak's Excellent Chinese Adventure shot.