Characteristically, Mansfield imports a term from her native New Zealand for effect: “brill” is a common fish without culinary or commercial value. However, clearly, Miss Brill is not a figure of contempt; her self-deception is a very human response to what she feels is becoming an intolerable reality; moreover, her apprehension of something at work inside her, alternately numbing and tingling, explains her displaced feelings and her need to fantasize.

Mansfield herself knew well the plight of a woman on her own living in exile: The last years of her life were a frenetic search for health on the Continent. The pleurisy that afflicted her in 1917 was later aggravated into tuberculosis; she died at the age of thirty-four near Fontainebleau, France, in 1923, when a coughing fit ruptured blood vessels.

In addition to the theme of exile, there is Miss Brill’s achingly human need to belong. The narrator’s adroit mediation between what Miss Brill literally sees and what her imagination invents accounts for her somewhat hysterical attempt to participate in life as more than a spectator. It is equally obvious, however, that to retreat into a fantasy world is merely to delay truth; Miss Brill’s shrill efforts to coerce others into her fantasy, such as the man and woman who meet in the gardens, becomes a way for her to participate in life without risking her emotions. What may in fact have been a man rejecting a prostitute’s solicitation becomes the basis for a rendezvous, until Miss Brill’s sense of identification with the woman in the toque reminds her too much of herself in the outward signs of aging and the losing struggle with poverty.

Finally, chastened by the snarling young man and the young woman’s mockery, Miss Brill is left without any defense other than the false sense of buoyancy she has conjured to protect her from reality. Alone in her room, she is unable to deceive herself, nor can she yet accept full knowledge of her condition. Still detached from her feelings, Miss Brill thinks that she hears the fox weeping. Mansfield’s husband—the author and editor John Middleton Murry—has said that Mansfield’s obsession for truth dominates her later, more mature stories, of which “Miss Brill” is an example.

"Miss Brill" depicts an afternoon in the life of a middle-aged spinster. During her customary Sunday visit to the park, she fantasizes that she and the park’s visitors are actors in a play. Her elevated mood is partly due to wearing her cherished fur stole. However, her high spirits are crushed when a couple sitting next to her mocks both her and her fur. Devastated, Miss Brill goes back to her small apartment and puts the fur away, imagining she hears it sobbing.

Alienation and Loneliness
Although Miss Brill doesn’t explicitly acknowledge it, her actions suggest she is a lonely woman. During her Sunday outing, she doesn’t think about any family members, instead focusing on her few students and an elderly man to whom she reads the newspaper several times a week. Even her name, Miss Brill, implies a distant formality; the use of her last name without a first name prevents any personal connection with the reader. Her fantasy, where she envisions the park-goers as characters in a play who are psychologically and physically connected, creatively illustrates her loneliness. However, this fabricated sense of belonging is shattered when the young couple on the bench insults her. When her illusion of play-acting is broken by the couple’s conversation, it underscores her alienation from her surroundings—showing she is detached and separate from the others in the park, with whom she only imagined a bond. Symbolically, this alienation is emphasized at the story's end when Miss Brill hurriedly returns her fur to its box without looking at it. This contrasts sharply with her earlier playful interaction with it, calling it her "little rogue." The story concludes by portraying Miss Brill as an isolated and lonely figure when she believes she hears her beloved fur crying as she puts it away, mirroring her own retreat to her "room like a cupboard."

Appearances and Reality
In "Miss Brill," Mansfield uses a stream-of-consciousness narrative to highlight the sharp divide between appearances and reality through the protagonist's thoughts. At the story's outset, Miss Brill is unsettled by an elderly couple sitting silently on a nearby bench, making it hard for her to eavesdrop on their lives. She fails to see that their silence mirrors her own quiet existence. Miss Brill also observes that the other park-goers are "odd, silent, nearly all old" and appear as if they "had just come from dark little rooms or even—even cupboards!" Ironically, she doesn't recognize that she is one of these peculiar people who live in a metaphorical cupboard. She also notices an old woman wearing a fur hat, which she refers to as a "shabby ermine," likely bought when the woman's hair was still yellow. When the woman lifts her hand to her lips, Miss Brill likens it to a "tiny yellowish paw." While she mocks this woman in her mind, she fails to see the similarities between the "ermine toque" and her own appearance. Later, Miss Brill imagines the park visitors as actors in a play and feels a sense of connection with them: "We understand, we understand, she thought." However, the illusion is shattered when an attractive couple, whom she imagines as the hero and heroine, reveal through their conversation that they do not share this "appearance" of a stage play. Their cruel comments show they are not "members of the company" who "understand." They dismiss her as a "stupid old thing" with fur that looks like a "fried whiting." The play—a metaphor that provided Miss Brill with a fleeting moment of clarity—exists only in her mind. This stark contrast between appearance and reality in "Miss Brill" accentuates the story's theme of alienation, underscoring how Miss Brill is isolated and estranged from her surroundings.