Textures seem to pop in-and-out on the Sylveon level.
It's a fairy simulation lab. What you're seeing is glitches in the simulation. It's all run by the purple core you see right before Sylveon's room.
Oh, thanks for telling me this. I wasn't sure if it was a bug or not. lol. It is indeed an interesting feature. I hope you are doing well Joshawott.
I am. Thanks.