Answer: The usage of the unreliable narrator and jumped pacing result in a mystery. As it is revealed in the beginning that the narrator is unrealiable, possibly from a mental disorder, and begains to talk about the wallpaper. The thorough description of of the wallpaper mostly through diary entries bring mystery into the story as the reader await to see what the truth about the yellow wallpaper. Hope it helps ( ◜‿◝ )