A person sits in a car with no money and no one for company, and yet the poem ends on the phrase "all the world." That gap between very little and everything is what drives it.
The first lines are bare: "broke and alone." There's no self-pity in the wording, just a plain statement of the speaker's situation. Then comes the candle. A single flame is a tiny source of light, but the speaker says it lets them see everything. The poem doesn't explain how, which leaves us to imagine it. Maybe the dark car and the flickering light make the speaker notice things more sharply. Maybe the world feels wide open precisely because nothing else is competing for attention.
The title, "Circumscribed," suggests being drawn around or limited, and the car is a small, closed space. Still, the mood isn't bleak. It feels quiet, intimate and oddly content, as if having almost nothing has cleared a space for seeing clearly.