And, of course, Batman, anticipating everything has his cape held secure against the slipstream.
Good eye, tho, I didn't even think about how WW's hair went one way and Sup's cape the other, but I think that's because I spent the glory days of Image (the early 90's, young ones) seeing too many artists have hair and capes blowing willy-nilly for no reason other than it "looking cool."
Btw, I've been plugging away at this one myself, but I'm having a bit of trouble with the light sources. The way I look at it, it's obviously the JLA satelite, in some kinda observation room--the moon, cloudy shapes, and number of small "x's" out the window prove this... But, as far as I can figure from the pencils, there it either one "spot" light source for the foreground (out of the picture frame, roughly above Hawkman)--Picture the JLA equivalent of a bare bulb, lol--or there are multiple light sources going on.
Batman's left in shadow [But GL's Ring is a secondary light source, probably responsible for the small rim higlights on the left of Bat's cape and cowl], Superman's right in shadow, Manhunter is lit directly from above, Flash is lit from the front, Hawkman is being lit from above-front Diana has no strong shadows at all, the gold of her costume reflecting all ambient light, which softly reflects from her marble-perfect skin, making her seem to glow in her own right [ok, that was overblown--she has no shadow, tho.].
Seriously, am I just wrong, or does it look like each character has his or her own special light?