If Zim pouting in the corner doesn't give it away, it's everyone's favorite trio, grown up, by my point of view.

Gaz is wearing glasses (All those videogames had an effect on her) and hasn't gotten her hair cut since the show, though she traded out her dress for a skirt and trench coat.
Dib is.... well, Dib. I dont think he ever grew out of that gangly phase.
And Zim is... taller... but thats pretty much it.

I do not own Invader Zim, any alterations to the characters are all my own ideas of how they would turn out if the show were ever continued (Starts petition)