The poem begins with a strange reversal: snow doesn't only fall, it goes back up, and that return is slower and more careful than the fall. As it vanishes, it stops being a blanket on the ground and becomes something more like the paint itself, wiping out its own trace. The speaker treats this disappearance as a kind of quiet effort, almost humble. The snow then hides in a cleft in the land and waits, and the winter hangs undecided, which fits the title's two-faced Janus, looking both back and ahead.
Then the tone turns playful. A witch hazel sizes itself up against an oak and announces it wants to be a tree when it grows up, listing what trees offer: a perch for birds, a city for insects, a home for lichens and fungi. The punchline is gentle and funny. The witch hazel already does all of that, just not as a tree. The mood is light, curious, and a little wistful, suggesting we often want a label for things we already are.