We received this image moments ago in an email from reader Tyler, with no text other than the subject "Charles Barkley Swapping Shirts with a Bro."
Now, it's safe to assume that Chuck is not wearing his own shirt. I think. It's possible he likes them tight, but he seems like the kind of guy who likes to stretch his shit out, not be all cramped and restricted. It's equally safe to assume that he did not swap shirts with the man with whom he is posing for the same reason.
It's a tough call, but I'm going to go ahead and say this is a shirt-swap and assume there is a half-naked man (or, possibly, a "bro") walking around somewhere just off-screen.