@Kampfarsch
You've misinterpreted something, clearly.
It isn't a world "shaped by cognition". It is just a world with permanent perception-screw status effects... or "cognitohazards" I believe the SCP fans called them, and resident lifeforms that communicate through the MEDIUM of such effects.
Even if I took a while to open up to the idea that one observer's perceptions in this place could have externalised effects rather than personal / internalised ones, that is still a far cry from "clap your hands to make it real" type remolding of the place. They're not screwing with the place itself, but simply the way it is perceived.