There are many semi-shocking things naked guys do. One is wear a hat. What are they trying to hide!? A second penis on their head? No, can't be that, else they'd be wearing very tall top hats, in case of erection.
I suppose the three guys wearing hats here (plus one with a headband) are just maintaining a sense of individual style, or just shielding themselves from the elements.
But to me, a hat on a naked guy just makes the rest of them look even more naked. Sort of like when a dick hangs out of an open fly. It's not so much about the clothing, but the contrasting dick. Though the singer who has managed to lose his pants on stage may find folks not fully connecting with his lyrics.
Unless they are something like "You're staring at my obscenely large, hard penis. Yes you are. Baby baby baby."
Though I realize he may not actually be a singer, but rather a stripper whose act involves the portraying an unknown rock musician at a local watering hole. Or possibly after the show, a well known cock at a local hole.
The guy standing in front of the porta potty is giving an X-ray vision into his behavior if he were inside it, at least the letting dick out of underwear part. Though he would find it difficult to pee through his erection, I'm sure he'd give it the old college try. Meanwhile, peeing through erections is pretty much what college is all about.
I can't much comment on the boxer weighing in. I get that boxing is a sport, but I'd rather see naked guys in alternative, brutish competition, like arm wrestling or chess.