Start with a "You Are Here" map, the kind you find in a mall or park. The speaker looks hard at the red arrow and the tiny dot it points to, and that small mark starts to grow. It becomes the dot on an i, the hole a compass leaves in paper, the bright spot the sun burns into your eyes. The arrow never quite touches it, the speaker says, because the dot is "too likely to spill," as if it holds more than a single place.
Then the poem turns. Everyone who stands at the sign sees the same message, so "you" becomes "you, & you, & you." The mood is gently amused, with a thoughtful edge. The last image, a whole note singing its "monotone song of yourself," suggests that each of us believes we're the center of things. The closing picture of "this head of a pin" makes that feeling both funny and a little humbling: we're all alone together, each on the same tiny point.