Three short lines, and a whole shift in feeling. The speaker says that the only person they can still picture themselves with is "you." The words "and now" suggest something has changed. Maybe other options have fallen away, or maybe the speaker has simply realized what was true all along. The poem doesn't say which, and that gap is part of what makes it interesting.
The mood is intimate and a little uncertain. It could be read as deep devotion, a quiet declaration of love. It could also carry a hint of narrowing, as if the world has shrunk until only one person is left in it. The plain, unadorned language makes the statement feel honest rather than showy. There's no grand promise here, just a simple admission. The short, spare shape of the poem, with "you" landing alone at the end, puts all the weight on that one person. It feels like something said softly, almost to oneself.