I have been reading about the flattening and how they are trying to absorb heat when they do that. But when I am holding mine she seems to really only do that when I get close to her cage. It kind of seems like she is doing it to say she does not want to go in her cage yet. Could that be the case or am I just starting to get to her cage every time that she decides to try and absorb the heat.
It sounds like she may getting startled, being carried is not a natural thing for them. Pepper flattens out if I move to fast, or lower him too abruptly.
They also do it to look bigger. They flatten out and tilt to face their back to a threat so that they look big and the tough, and their protective back scales are exposed instead of the soft belly skin.
Pogi does that too when basking or when she is starting to chill out in her bath. She also will do it when I am petting her. I like to think it is also because she is relaxed and enjoying herself.