If it were possible for GLaDOS to take complements as anything other than the other person trying to gain some sort of logical advantage in a very illogical manner she might have been affected by Remy calling her pretty. Instead she had to work to turn the complement around on him; use it to make her the one with an advantage. GLaDOS' programming told her that Remy was probably most often accustomed to using sexuality and complements as a way of control and/or disarming. GLaDOS would neither be controlled nor disarmed.
Remy's question was rendered moot as the female skulked away. That left the computer with a Cajun on her hands. Clearly the Cajun was going to go get her cake. That would be acceptable.
GLaDOS was slipping out of the Cajun's grasp as she started moving off in her own direction. She wasn't going after the woman, at least not obviously. No, she was on her way back to the Post Office.
Oh, let's not forget the wink she cast over her shoulder at her Favorite.