Jessea L. Vaughan's poem is about feeling invisible, even when you're surrounded by people. The speaker begins by asking us to imagine being a "face in the crowd," then piles up words like "unremarkable" and "indistinguishable" until the person seems to vanish into the mass. The repeated phrase works like a label that keeps getting stuck on.
The feeling here is loneliness, but with an edge of desperation. Being among thousands and still feeling like you're on a "desert island" is a sharp contrast. The "nosebleeds" suggest a stadium or arena, and the image of someone waving and screaming, trying to be seen, is both sad and a little painful to picture. The final lines hit hardest: "Until you go home." It hints that the person only stops being anonymous in a private place, or perhaps that nobody notices them at all. The mood is wistful, aching and quietly bleak.