movement and posture headcanons!
If you can get Chromia to dance, I don't see her being all that elegant like, say, Windblade might be. She's very rugged, and unhappy where she is now, and she doesn't seem like someone that'd want to do something that could possibly break that appearance she's set up for herself.
So, should she be forced/convinced to dance, Chromia would likely shift her gaze around, watching everyone and everything to make sure she wasn't the center of attention while her feet would shuffle awkwardly from side to side.
She'd be stiff, uncomfortable, and ready to quit at any moment.
Now, if she was alone with whoever it was, in a private area, she might eventually relax, and her movements would soften, would flow, easier.
Enjoy a big awkward mech in blue.