What's more romantic than the moon in June? When George falls hard for Mary, he asks her:

GEORGE: What is it you want, Mary? What do you want? You want the moon? Just say the word, and I'll throw a lasso around it and pull it down. Hey. That's a pretty good idea. I'll give you the moon, Mary.

MARY: I'll take it. Then what?

GEORGE: Well, then you could swallow it, and it'd all dissolve, see? And the moonbeams'd shoot out of your fingers and your toes, and the ends of your hair ... Am I talking too much?

Like the cigarette lighter, this image is a romantic reverie of how things will magically be wonderful. The moon symbolizes those impossible but marvelous aspirations for the future. Later, when Mary shows George the old, dilapidated house where they'll begin their life together, she's made a sign that says, "George Lassos the Moon." Mary is telling him that anywhere can be the moon if you're with people who love you. Aww.