The black/pink-headed girl in the gray Todd shirt is Liz from Freezepop, yeah, and I'm going to go ahead and guess that, since the band is all in love with Achewood and similarly vice versa, the "Sean" who took the pictures is also in the band as well (he plays Casio).

That said, who are the other three girls in the picture? I can't really place the redhead but I KNOW I've seen the orgasm-looking one in the Rabbit Ambulance shirt, and the blonde in the "Everybody Dance" shirt, many times before.