The appearance of old and young characters is a motif throughout the story. Miss Brill looks favorably on young people, romanticizing their lives to an unrealistic degree, while judging and dismissing old people who seem to have more in common with her.
In the beginning of the story, Miss Brill finds herself sitting by two elderly people, who remind her of a couple she saw the previous Sunday. Recalling the couple's conversation, she characterizes them as dreary and boring people, emphasizing the tediousness of their arguments:
"An Englishman and his wife, he wearing a dreadful Panama hat and she button boots. And she’d gone on the whole time about how she ought to wear spectacles; she knew she needed them; but that it was no good getting any; they’d be sure to break and they’d never keep on."
By contrast, Miss Brill sees young people as inherently vibrant, beautiful, and fortunate. When the young couple sits down next to her, she envisions a glamorous backstory to their relationship, even though she knows nothing about them:
"Just at that moment a boy and a girl came and sat down where the old couple had been. They were beautifully dressed; they were in love. The hero and heroine, of course, just arrived from his father’s yacht."
This motif reflects Miss Brill's internalized self-loathing and her tendency to fantasize about her own situation: even if she won't admit it, Miss Brill is obviously one of the old people she despises. By praising the young and disparaging the old, Miss Brill identifies with the people she considers happier and better-off in life. Throughout the story, the reader can perceive the irony of Miss Brill's preference for young over old. But she herself only snaps out of her delusions at the end of the story, when the young couple's insults show her how others really perceive her.
While the distinctions Miss Brill draws between young and old may be the product of her own fantasies, the way these different groups behave towards each other signals a broader lack of affinity between generations. The old people at the park seem to have little interest in the young, while the young view their elders as inherently boring or burdensome. Like many other modernist writers, Mansfield is concerned with the way individuals relate to their broader environments, and it's clear that the loneliness and alienation Miss Brill experiences personally is occurring on a societal level as well. Mansfield uses the motif of young and old to show how modern urban life has threatened intergenerational community.
