The unusual meandering tone of the film may be unsettling for some. When the movie tries to be creepy however, it does somewhat succeed. A good example is when the main character is searching a musty attic and suddenly realises he might not be alone up there. There is a lingering dread of something unknown being kept in said attic that might be unpleasant.
Someone is suddenly seen sleepwalking. This is tame, at least until his behaviour becomes extremely erratic. Could be disturbing for some.
A series of macabre hallucinations. It is unclear which of these are actually happening.