this wasn't the girl he knew. this girl was scary, beautiful, grace and elegance personified. with the power of two witches inside her, she walked as the most powerful being around- besides him, he reminded himself.
Remember how Elsa used flowers and added them onto her dress in Frozen Fever? Jack is training Elsa for that right now. She is trying not to freeze the flower crown. (Anna and Rapunzel had to teach him how to make them)