Here's what it tells us about the narrator's mental state:
* Triumphant Liberation: The phrase "I've got out at last" signifies a sense of victory, but it's a warped victory rooted in delusion. The narrator believes she has escaped something, but the reader knows she's actually become trapped in her own psychosis.
* Defiance and Rebellion: The "in spite of you and Jane" declaration reflects a fierce sense of rebellion against those who have tried to control and silence her. She is no longer willing to submit to their authority.
* Symbolic Act: The act of "pulling off most of the paper" is a symbolic act of liberation and defiance. The yellow wallpaper has been a source of both fascination and torment for the narrator, representing her confinement and the oppressive nature of her treatment. By destroying it, she believes she is breaking free from her constraints.
* Delusions of Agency: The statement "so you can't put me back!" indicates a delusional belief that she has gained ultimate control over her situation. She has become convinced that she is free, even though she is clearly unraveling.
The ending leaves the reader with a sense of profound sadness and a disturbing glimpse into the consequences of denying a woman's autonomy and intellectual capacity. The narrator's final victory is a tragic one, highlighting the dangers of societal and medical practices that fail to acknowledge and address mental health needs, especially for women.