Now I believe, left to right, that we are looking at Green Lantern, The Flash, Aquaman, Batman, Superman, The Atom and Hawkman.
And now, left to right, I will review what they are wearing.
If you were the Green Lantern, and your super hero costume was a high-collared green top and some black pants, would you choose to wear a green turtleneck and black pants for your street clothes? Basically he is only missing the flimsy domino mask here. That's a poor disguise, Hal.
Ah, Barry Allen. A man of no style. Or, at least, a man of very conservative style.
Actually, I say that, but if I saw a man wearing a yellow or gold three-piece suit, I would think it was pretty daring.
As if it even matters what anyone else is wearing because the only guy you are going to notice in this crowd is Aquaman. This daring number seems to boast "Hey, Green Arrow, THIS is how you wear a lace-up shirt." It's possible, of course, that Aquaman really has no idea what "street clothes" are. And who could blame him?
We can't see Clark Kent from the neck down here, but let's assume he's wearing an over-sized, rumpled affair that his mom bought him. Or we can pretend that he is hiding behind Bruce Wayne because he is embarrassed to be wearing the same outfit as Aquaman. Whatever you prefer.
Ladies and gentlemen, Bruce MF Wayne. Here's a man who looks like a million bucks, because he spent a million bucks on his coat. And this really works as a disguise because you wouldn't look at this guy and think "I'll bet he's Batman." You think "I'll bet Batman wants to be this guy."
We can't really see what The Atom is wearing. In fact, I am not even sure that is The Atom. I just assume it is. It could just be some guy running for the train who got caught up in the JLA posse at this exact moment.
So what has caught Hawkman's attention? An attractive lady perhaps? A police siren? I would actually guess that it's his own reflection in a shop window, because he looks so damn gooooood. He's just strutting down the street, singing his private themesong in his head ("Hawkman is swinging, Hawkman is swinging, Hawkmaaaaaan... Hawkman swinging") wondering if he should maybe undo another button. The fact that he's wearing a shirt at all, and not wearing wings and a hawk mask, makes this a pretty good disguise.
Panel taken from Justice League of America v.1 #89, one of the most insane and self-indulgent comics ever written.