In that case, it's probably just normal social signaling behavior.
He's feeling warm and toasty over there and it's inspiring him to act up a little bit. XD
Lifting the tail is just a sign that the dragon is feeling awake and alert, or playful, unless it seems really obvious that it's trying to keep its body from contacting a surface. Armwaving and footstamping can mean a lot of stuff, but, speaking very generally, arm-waving is a submissive or at least nonagressive gesture whereas foot-stamping is a dominant, I'm-in-charge sort of gesture. Depending on your dragon's age, he may do all of those things just for practice or the sheer fun of it, too.