The woman behind the wallpaper in Gilman’s short story represents the personality of the narrator. Throughout the plot, she falls into madness and seeks an escape. That’s why she identifies with the woman presumably kept behind the yellow wallpaper.
Detailed answer:
The Yellow Wallpaper is a story written by an iconic American writer Charlotte Perkins Gilman. It was published in 1892 in The New England Magazine. It is a pioneering piece raising a discussion over feminism and the mental health of women.
The story draws a picture of a couple renting an old mansion for the summer. John is the husband and a physician. He believes that his wife needs rest to cure her nervous depression. So, he isolates the woman and doesn’t allow her to do anything. The wife soon starts seeing a woman hidden behind the yellow wallpaper that she first hated. In the end, she loses her mind. The character believes she is the woman behind the wallpaper. She cries: “I’ve got out at last.”
The story demonstrates the gap between female and male characters. John has no idea how to treat her condition. His approach doesn’t work and intensifies his wife’s insanity. That’s how Gilman criticizes the male dominance in medicine, typical of the XIX century. But madness gives her a chance to escape the patriarchal system.