In Miss Brill, there are allotments of secondary individual characteristics and Katherine Mansfield conceives them with reasons.
The old couple who don't speak at all are the same as Miss Brill who keeps listening to the other people without any words on Sundays.
Already knowing that Miss Brill is lonely isolated and rejected from other people just like the ermine toque
The extreme contrast of brightness and darkness makes the darkness even darker.
The young couple who makes fun of Miss Brill makes isolation even deeper by breaking her fantasy.
In short, all the minor characters are concentrated on showing how Miss Brill is lonely and isolated and highlighting it with various ways.
Critical Analysis
In thinking of stories that I've read, secondary individual characteristics don't actually have important cause in the story. In Miss Brill, there are allotments of secondary individual characteristics and Katherine Mansfield conceives them with reasons. Mansfield values the secondary individual characteristics to focus Miss Brill's solitude and isolation. They are split up into three groups: the passive and uncommunicative, the hardworking and communicative, and eventually, the juvenile twosome who is shown at the end. (Katherine pp.52-89)
There's the story the way it is seen, a wonderfully structured thing with a fine harmony of irony and symbolism. Needless to say, students don't catch all these subtleties right away. But they all respond to the story, even though at first they are unaware of what they are responding to. And when they have determined some of the elements that make the story work, they have had a worthwhile literary experience. They have Katherine Mansfield's “Miss Brill” in hand as a letter of introduction to some of the more aloof Dubliners.
The passive and uncommunicative assembly of persons, particularly the old English twosome and the ermine toque contemplate Miss Brill's solitude and isolation by their needs of interaction. These persons don't combines with other ones, and this isn't distinct from Miss Brill. The old couple who don't speak at all are the same as Miss Brill who keeps listening to the other people without any words on Sundays. The Englishman and his wife seem to talk each other. However, they, especially the old lady, only speak their words not to listen to the other. In other words, their conversation lacks interaction and Miss Brill also does. Besides, Mansfield uses these characters not only to reflect her loneliness but also to highlight ...