My personal guess is that you're long-time companions (each from a different world) and you often carry the other one if she gets hurt or sick. Nothing's gonna stop you from your way across the wasteland. That's what I see in this picture. Kudos for that pose, girls.
the emotion in this one confused me a bit. at first i thought that she was happy, perhaps she killed/knocked out the other girl, but then i thought that didn't make to much sense, so then i figured that someone else did that and now she is pissed. Kind of hard for me to tell though...
I like this picture, obviously the girl being carried is either dead or unconcious HOWEVER it does also give the impression that the girl that is carrying the "unconcious / dead" girl has like a power over the carried girl.
almost as if to say.. "you're mine and theres NOTHING you can do about it.. I think I shall take you over there and you can't stop me.. muahahahahaa"