Loki wrote:

Sidney Osinga wrote:

Page 2, panel 2: in the top left corner, the object being held by the primitive-looking man with the red cape looks like a Dogū https://en.wikipedia.org/wiki/Dog%C5%AB
The girl in front of Lightning Boy is Saturn Girl, even though her costume lacks its' usual colour.

Page 3, panel 2: the alien on the left, running the Snacks booth, is Dexter Jettster from Star Wars: Attack of the Clones.
On the right end of the panel, beside Rusty Venture, are his friends Dr, Billy Quizboy and Pete White.
(White, in case you don't know what he looks like)

Yes to all of those except perhaps Saturn Girl. I have to admit she was the first person I thought of, but when I checked Saturn Girl's costumes I couldn't see one that matched this one. It's possible that she's a bit off model, but everyone else is on point, so I'm hesitant to confirm for certain it is her - I'll put her down as a likely, but not confirmed.

I'm sure that it's Saturn Girl, despite her costume being white. It looks like the version she wore in her first appearance.

And it makes sense that it's that version who's standing right by Lightning Boy; neither wore those costumes again (kind of surprising because they're both decent looking costumes) and LB was LL in his next appearance; they probably travelled there together.  Proty came later but he's far enough away from them that it doesn't matter as much (he could be from a different time or this could be a younger Proty).