There’s not much difference between dream state and waking state.
Certain things are shut off. Our ability to move our bodies is mostly shut off. Also, in dreams there is no genuine “background”; it may be in “full screen” but it is more akin to a movie, which gives it that “disembodied” feeling while within them.
For example, I may see a night sky and be flying through it. It’s all around me. Yet, it can be ripped away like a scene in Inception just as quickly. No sense of permanence to backgrounds.
[PS – Inception was not a movie about dreams. It was a movie about filmmaking, hence the editing]