The line “[w]e are continents, worlds apart” from the poem “tattoo” by gregg shapiro is an example of which poetic device?

This line from the poem Tattoo, by Gregg Shapiro contains an example of a poetic device known as metaphor or simile.

Explanation:

The speaker compares themselves with continents, worlds that are apart and the metaphor is a literary device that refers to a meaning or identity ascribed  to one subject by way of another. In a metaphor, one subject is implied to be another so as to draw a comparison between their similarities and shared traits. In this case, the speaker compares themselves with worlds apart to express the differences, the distance between the two subjects.