Explain the rhetorical purpose of the image that begins the third stanza.

The third stanza begins with an image of the lovers gazing into one another's eyes. They each see their own faces reflected in the other's eyes, like a mirror, and they can see that their faces are full of "true" and honest love (line 16). This image echoes stanza two's idea of each lover as a world that the other can be immersed in--but it adds a sense of connection between them. This connectedness sets up the poem's final contention, that the two lovers are like the hemispheres of a single planet.