I've come up with an explanation to logically explain the drastic change in art direction Portal 2 is compared to Portal 1 in the lore. Wheatley mentions to Chell after she wakes up that there's a possibility that she might have brain damage from how long she was asleep in the relaxation chamber. This brain damage idea is backed up even further when instead of saying "yes" or "apple", Chell instead jumps. You could also count the fact Chell never speaks in Portal 2. Chell "somewhat" had a voice in Portal 1, just reused Half-Life 2 female citizen pain voice lines. This could explain why the wallpaper and painting in the relaxation chamber change after Chell wakes up a second time. In reality, the decor in the room could've always been a painting of a night sky, and the wallpaper with a wolf. It's just Chell's memory could've been impacted enough to remember the decor in the room completely differently. This goes back to the change of art direction of the Portal games. Along with the decor of the relaxation room, Chell's entire memory of the events of Portal 1 would've been altered drastically. This includes Aperture machinery, puzzles like the energy ball/laser chambers, the outside surface of Aperture Science, Chell's own appearance, and the appearances of personality spheres and of course GLaDOS. During Portal and the beginning of Portal 2, we play through Chell's warped memories of those events. How the brain works, if a memory is altered, it can completely change your perception of that event and you'd think that it's always been a certain way when it hasn't. So from our perspective, it's always been how we see it. What do you think of this theory? I had fun writing this! :D
I like this theory, May even contend with my personal headcanon.
I think that's a pretty good theory.
Actually we have a theory about that Chell is Eli Vance´s wife and Alyx mother. This thing is very usefull for our lore
The real question is: Is the cutscene of the cake inside the room with all the cores in it, at the end of Porta l1 actually Chell dremaing?
followed. have a great day.
Thank you my good sir. :)