Copy Cat, or CC for short, is a psychic alicorn that was broken in the sense that she lacked any identity of her own, and rather formulated one on the fly by psychically connecting to anyone nearby and shutting down entirely when there was nobody around to give her a sense of identity. In this case, she's scouting out some toxic and super irradiated ruins for the rest of her friends, since she's immune and they're not. Her home town is starving, and they're all looking for salvage to rebuild the settlement, anything they can trade for necessities, or otherwise a way to make it a viable town once again. I believe this scene takes place in the ruins of Stalliongrad.