It's simply her avatar visually representing her character growth imo. You could even argue that its bc the MC sees her in a new, uglier light after what she does to him. Even if you, the player, see her in a different light. I fully agree, but DPC bait and switches the MC with her. This is a chick that's willing to stab her new friend/boyfriend in the back for an opportunity that is clearly a fairytale. She goes from being a very kind, sweet character on the surface to lying or omitting everything especially if it would impact the decisions of others in a remotely negative way.
Maya's changes are made even more stark in contrast by the fact that several other models actually improved at the time hers got so much worse. In literature such shifts, though non-visual, are pretty damn common. The author starts with a deep passion for a specific character, but then moves on to characters they connect with better. And while Maya starts off pretty perfect, her character does things that would instantly kill many relationships. Repeatedly. After all, Maya is the one character, that no matter your decisions, behaves in manner that most people would consider cheating.
