First off, that is one great lookin' Mojo!

Hard to say what the issue might be. Could be a phase she's going thru. Might be early pre shed behavior. Could be any one of a million things we'll never think of. It's good news that she seems to relax after the initial defensive behavior. To be honest, I think a lot of young BPs will do that. Just a built in mechanism courtesy of Mother Nature.

Best advice I've ever gotten in this hobby: "Sometimes ball pythons do weird crap"