Oh, Shmoop is a home where the buffalo roam, where the nerds and the coolest kids play; where never is heard a discouraging word, and the Shmoints do flow freely all day.
The narrator believes she has made a breakthrough. She believes the front pattern of the wallpaper moves because the woman trapped behind it is shaking it.
The narrator thinks the woman is trying to escape, but the pattern of the wallpaper is strangling her. This, thinks the narrator, explains all the heads and the bulging eyes.