I'm not going to take pictures with my girlfriend.
Why don't you want to take pictures with her?
I don't like the way she looks in pictures and I don't want to be seen with her.
It's not right to refuse to take pictures with your girlfriend just because you don't like how she looks in them. If it's important to her, you should be willing to take pictures together.
I'm anyway not interested in pictures and I'm fed up with this so I'm just going to leave.
If your girlfriend wants a picture with you, it should show you how much she appreciates you and wants to see you when she's not around. Refusing her because of how she looks in photos is really cold and you may want to talk to her and apologize.