What I've gathered:

[Spoiler](/s "The dream was created by the old dude in the wheelchair that is inside the dream. The video (and game) makes many mentions of having "eyes inside" needed to see more. I believe the blood you, and the other hunters, are transfused with at the beginning of the game gives you the "eyes within" that are basically insight only intended for other hunters. That's why the more insight you get, even in the dream the more you start to see what is really there. The dream is just a copy of a place that the hunter likely found comforting, hence why we can find a duplicate of it in the real world.

The dream is just a hub. It's a reprieve, hence it being a recreation of a place that is friendly, pretty and comforting in the real world. It allows hunters to take breaks, upgrade their abilities and some other things. It might be better named the "Hunter's Reprieve" than "Hunter's Dream" since, even though it is outside of reality and likely only seen through the eyes in our head (insight) given to us in the initial transfusion, it affects your reality. Even though it is a dream, it seems to sort of not be. It seems to be a real place, only within the heads of those who have the eyes inside to see it and to exist in it.

I guess I'll sum up by saying I think it's a dream, but it's also very real. What is a dream, anyway? It's something we create/imagine inside of our heads when we close our eyes. So what if we have eyes in our heads that allow us to see things while we close our eyes that have an actual affect on our real world when we awake? Our eyes are closed, we are asleep, yet we are aware and we are affected. It's something that a person without insight that may drive you insane couldn't possibly understand, but to a sane person what we are doing, where we are going, is indeed still a dream...)