What is an example of an extended metaphor in The Yellow Wallpaper?

An example of an extended metaphor in "The Yellow Wallpaper" is the narrator's comparison of the wallpaper in her room to a prison or cage. Throughout the story, the deteriorating wallpaper symbolizes the narrator's own mental state and confinement within her oppressive surroundings, creating a sense of entrapment and confinement that mirrors her own psychological deterioration.