Me with Prinelence at the Thuerigan Lakeside

the Dance pose only available if one of your character become Veteran. after you become Veteran, head to Cite de Reboldeux and go see Andre. He will congrats you and give you the Pose Guide vol.10. p.s: ignore the question mark on his. you won't have any quest with him unless you already trigger 'Reckless Emilia' quest