Beauty. That was all she ever saw herself as. Another pretty face when she was so much more. He had the choice of a lifetime. For her. He couldn't risk her soul. From the moment she had entered his studio she turned his world upside-down. She had made him (somewhat) compassionate. She had made him protective. All he had ever wanted was what was best for her. It had killed him at times.
He was who he was. He became the best to cover his insecurities. She wasn't afraid to fight his nature, a cruel beast at times. He now had to fight for her. She was so much more than a mere pallet for color and other's manipulations. That is why he chose the other girl. For her.
He couldn't be the one to do it. To tell her to turn her head left instead of right. Chin down, eyes up. He couldn't be the one to put out her fire. He refused too. She knew better than most. She was perfect, tear-streaked and perfect. Beauty, anger, tears, fire. It was her. He couldn't be the one to manipulate her soul into some mere mannequin. She was so much more.
So as he watched her storm from his studio he knew he had done what best. Maybe it wasn't for her. Her beauty, her fire, her existence was bound to change after her star had slowly risen in fashion. Slowly her fire would be lessened. So he did it for himself, so he wouldn't have to be the one to put out her flame. It would kill him to do so. He cared for her, plainly, organically, no make-up, no one to impress. Her frustration, her anger, her defensiveness. Her faults that made her the true beauty that she was.
He knew that no one else would ever see her as he did. They would see the submission. The delicate features bending at will. If she were to do that for him it would make him sick. She wasn't mallible. She sturdy. Meant to be enjoyed as herself, not as the mere puppet of those lesser then her. She would never see herself properly.
She ran from him not knowing his heartache. Not knowing why. She merely saw the destruction of her career not the preservation of her soul. He did. He saw her soul and knew that any cost was worth protecting it.