My understanding is it sort of relates to a simulated acoustical physical space the music is intended to seem as if it is reverberating throughout
Is it correlated with the intimacy or closeness of the music, what else does it evoke? What is its relationship with artificiality and nature respectively?
What is its evolutionary purpose in terms of why we can parse and interpret it?
I think it just informs us about the physical space we are in. That can be used in a lot of ways emotionally. A small space can feel intimate or claustrophobic. A large space can feel freeing or uncanny.
What does uncanny mean in this context?
Like strangely large. You ever look into a deep pool and get spooked by how deep it is? I was once on a small boat in a cave and Jesus the water was so deep. You could see so far down and it gave me the creeps.