How is urban life portrayed in "The Love Song of J. Alfred Prufrock"?
The loneliness of the narrator helps to underscore the loneliness portrayed in the description of the city scenes. The narrator is unsure and isolated, feeling like a bug "pinned and wriggling on the wall." He wishes he were only a "pair of ragged claws" and not a member of society. He worries about his fashion and about his appearance, particularly as he ages. He talks of the room "where women come and go" and implies he has spent much time in this room - "I have measured my life in coffee spoons." However, he doesn't really know this people. He can't be sure that he is understanding anyone, which is why he won't speak up, afraid that the lady will say "that is not what I meant at all."
By first describing the city scenes, and then the feelings of the narrator, Eliot makes it clear that the loneliness of his narrator is the loneliness of the city.
An interesting question. We might rephrase it slightly, and ask, what elements of urban life are represented? If we ask it that way, we see things like "half-deserted streets," and "one-night cheap hotels." We see people talking idly—but not to the narrator—and lonely men. We see dirt. The result? Urban life is portrayed as isolated and isolating, the sight of alienation. There's little sense of community, or of the richness of the city, but rather, lonely vice and only limited connections among people.