Noelle feels like she's been "watching herself through the glass." Sound familiar?
You looked through the glass.
For some strange reason, for just a brief moment...
It's as though her actual self is forced to watch an alternate version of her life play out. This backs up the fucked up timeline theory I've seen in this thread btw.
Someone else is moving Noelle through her life for her? If we take what she's saying here at face value, she either:
1. Is self-aware that she is code in a video game and has no free will (most likely).
2. Also has a SOUL (this is a stretch).
Obviously this monologue exists as a parallelism to Kris but it makes me wonder if she has a similar situation going on.
Kris has to do "Kris things" and Noelle has to do "Noelle things". The story of Deltarune is deterministic; there are no real choices, characters will only act within the bounds of their pre-determined code and only by exerting our external will on the game and by extension literally breaking it can we change that.
If you're of the opinion that chapter 4 weird route was a metaphor for rape then you may have noticed the lake scene also has sexual overtones. After reaching a certain depth in the lake
Kris can't stop and can only proceed, Noelle gets more excited throughout and there is even a climax at the end. Seriously, reread the dialogue through that lens and you will see what I mean. (although I could just be dirty minded).