Four short lines, and the strangest thing about them is who does the talking. The speaker isn't there. While he is away, a guitar takes his place, telling his wife about love and war, sand and water. These pairs pull in opposite directions: tenderness and violence, dry land and the sea. Then the guitar "showed the ships to my wife," as if its music were strong enough to conjure whole scenes, boats on the horizon, journeys, departures.
The speaker doesn't say how he feels, but the details suggest it. There is a gentle ache in imagining his wife seeing, through music, a world he can't share with her at that moment. The word "absence" ends the poem and leaves it hanging. The mood is quiet, wistful, and a little dreamlike. It reads as though the speaker is half grateful that the guitar kept her company, and half sad that he wasn't the one to do it.