In Charlotte Perkins Gillman's "The Yellow Wallpaper," her narrator's tone is passive, disturbed, paranoid, and intimate.
The narrator is torn between sanity and sickness/insanity; masculine and feminine roles; and the freedom of nature and the prison of the domestic bedroom. So says Enotes:
Since the protagonist is suffering a mental breakdown, she is also considered an unreliable narrator because the reader cannot be certain if she is accurately relating the events of the story. This adds emotional impact to the narrative because the reader is given an intimate account of the protagonist's growing feelings of despair and confusion.
Here's a few quotes as support:
There is a delicious garden! I never saw such a garden large and shady, full of box-bordered paths, and lined with long grape-covered arbors with seats under them.
There were greenhouses, too, but they are all broken now.
There was some legal trouble, I believe, something about the heirs and coheirs; anyhow, the place has been empty for years.
Then I peeled off all the paper I could reach standing on the floor. It sticks horribly and the pattern just enjoys it! All those strangled heads and bulbous eyes and waddling fungus growths just shriek with derision!
I am getting angry enough to do something desperate. To jump out of the window would be admirable exercise, but the bars are too strong even to try.
The fact is I am getting a little afraid of John.
He seems very queer sometimes, and even Jennie has an inexplicable look.
It strikes me occasionally, just as a scientific hypothesis, -- that perhaps it is the paper!
There comes John, and I must put this away, -- he hates to have me write a word.