Zim went back in time to test out a time machine. He chose to return to his days as an irken elite, back when he was younger. And we all know if Zim ever met up with himself, he'd try to molest him. Fr srs.
Invader Zim is a bit unnerved; he doesn't remember being this horny back in his elite days. Surprise, Zim!
For those that are wondering WTF the past Zim is wearing... why, that's his elite uniform, of course. Took the design from the Zim wiki's concept art from The Trial.
LOL, enjoy.

Zim is (C) to JV