The paper gives the impression that there is "a woman stooping down and creeping about behind that pattern." She fancies that the paper is moving. The pattern moves, the wallpaper's influence creeps into the house, and she projects her obsession onto John and Jennie, who seem to stare at the paper like she does when they have an unguarded moment. The once-acknowledged imaginary woman becomes 'real' by the end of the story, shaking the paper and creeping about by day -- finally, at the story's end, the narrator has become the trapped, wallpaper-encased woman in her mind, and completely mentally unraveled as a result of her rest cure. This shows how the wallpaper of the former nursery room of the home symbolizes that woman is trapped by her rest cure, and by maternity. The narrator, unable to express her anger and sadness, instead expresses these feelings by developing a fixation on an imaginary woman, the projection of all...

Even as she becomes delusional, the narrator seems less obtuse than her uncaring physician of a husband, who cannot acknowledge that the mind can influence someone's state of physical health, or see that his wife has needs beyond that of maternity and domesticity.
The narrator, even though she is mentally unbalanced, is also sane in the sense that she sees that she is trapped, and she needs to write, not to rest her mind. The fact that the story is narrated in the present tense makes the tale more effective, because the narrator is not forced to pass judgment on her former self as either oppressed or insane. Instead, the reader comes to understand how the narrator unraveled, by seeing the world through the narrator's eyes.

Works Cited

Gilman, Charlotte Perkins. "The Yellow Wallpaper." 1899. [1 Feb 2007] http://www.library.csi.cuny.edu/dept/history/lavender/wallpaper.html