Painting, boobs and butt style
The swinging motion at least makes sense for the boobs and butt pose, although it is convenient we're getting a kinda upskirt angle.
Also, apparently she's doing her mutant power which is "painting with truth" and now I'm trying not to think of Bob Ross in a boobs and butt pose.
(Panel from Legion of X #1, Marvel Comics, Submitted by Anon)