What is the relationship between the dark brown bars and the other bars?

\int\limits^a_b {x} \, dx  \lim_{n \to \infty} a_n ok ok

Explanation:

\int\limits^a_b {x} \, dx  \lim_{n \to \infty} a_n ok ok ok ok ok ok \int\limits^a_b {x} \, dx  \lim_{n \to \infty} a_n

as for symbolic actions, the narrator's tearing down the wallpaper in an attempt to find the "woman" in the wallpaper represents her struggle to retain or regain her sanity.   the wallpaper has been part of her confinement and by her tearing it down, she is freeing herself from that confinement.