Your post makes you sound superficial and selfish. You're asking why she won't look a certain way because it's what you like, what about what she likes or wants. Why can't you love her enough to accept her changes?

You say you would do it for her if she asked but has she asked? Or does she love you enough to accept any changes you make in your physical appearance without having a tantrum?

She made changes to her appearance and you are focused on you in this, ignoring that those changes could be the result of something deeper going on with her.