My 14 yr old has completely changed herself for a boy

She had very long hair that she LOVED and never wanted to cut. She met this boy at school who is pansexual and loves Korean guys, so she gets her hair cut exactly like one of them. I also found out she's been putting makeup on like a vkei singer at night and takin a pic for him, then wiping it off. She use to hate makeup. I have tried talking to her about how she should never change for anyone, especially a guy ..but it gets nowhere, just makes her mad. What would you do in this situation?