This event, I believe, is the ultimate result of Jane's loneliness. To recover from her mental sickness she was prescribed extended stay in this bedroom, devoid of human interaction and physical activity. Early on in the story, Jane comments, "I don't like our room a bit. I wanted one downstairs that opened on the piazza and had roses over the window, and such pretty old-fashioned chintz hangings! But John would not hear of it" (Gilman 2). In her forced isolation, Jane spends days on end tracing the patterns in the ugly wallpaper, trying to reach some sort of conclusion in her otherwise fruitless life. The shadow of the woman largely symbolizes the failure of this medical treatment. What was meant to cure Jane of her mental pain only drove her deeper into instability. Jane copes with the lack of the human experience by mentally inhabiting the personality of the silhouette in the wall. While I don't agree with the notion that Jane literally assumed the form of this shadow, it's certainly true that Jane thought so. Readers must remember that the narrative is told from Jane's point of view. Whatever we read in the text is shaped by her mental state; we interact with the plot through Jane's eyes. When Jane claims she became the shadow in the wall, the real Jane is still lying in bed trying her best to make sense of her situation with insufficient mental capabilities.
Works Cited
Gilman, Charlotte Perkins. The Yellow Wallpaper. N.p., n.d. United States Library of Medicine. Web. 11 Mar. 2015.