Question

a white vet’s image floats
closer to me, then his pale eyes
look through mine. i’m a window.
he’s lost his right arm
inside the stone.
—“facing it,”
yusef komunyakaa

which device is “i’m a window” an example of?

Explanation:

To determine the literary device, we analyze "I'm a window". A metaphor directly compares two unlike things without "like" or "as". Here, the speaker is compared to a window, implying the vet's gaze passes through them as through a window, making it a metaphor (not a simile, which uses "like"/"as", or other devices like personification or hyperbole).

Answer:

Metaphor