Dave Bonta's speaker looks back at a childhood keepsake: a shark's tooth, probably bought as a souvenir. He isn't even sure where it came from, guessing that his grandparents brought it home from a cruise. The opening question, with its sneer at a "tacky tourist trap," sounds almost embarrassed, as if the object were cheap.
But the tone shifts as the poem goes on. The boy carried the tooth in his pocket like a lucky charm, and the speaker clearly still feels its pull. The tooth is tiny, yet it makes him imagine rows of teeth like mountain ranges and a fin circling in the water. Its color, like old leather or dried blood, adds a hint of violence.
The ending is the most striking part. The tooth is shiny enough to act as a mirror, but what it shows is "not quite my reflection," something sharper than a shadow. The poem suggests that a child's trinket can still carry a flicker of danger and an unsettling sense of self.