You've left something unfinished. I know that can be vague but it must be something you're unsure of since the path to the end is malleable like cardboard. I wouldn't say this relates to claustrophobia, unless it does for you in a way, like the project in real life is on a linear path with no possibility of diverting course. The final result is simple enough, hell the door was open and you saw a result you envisioned reaching at the other end. The liminal space is created by curiousity, since you were in a place you both understood and didn't.