The idea is that the reader catches a persepctive that the narrator is slowly sinking into madness. Is there really a woman creeping around outside in the bushes? Probably not. Is there really a woman trapped in the wallpaper? Definitely not. But is the pattern of the wallpaper interesting and confusing? Probably yes.
Books have more detail while movies show more of the facial expressions one may have. Movies also have budgets, while books often times do not. Books do not need paid actors or a million dollar set.
