The poem sets two things side by side: a delicate image of the night sky and a thought that drags the speaker back down to earth. An "inch-and-a-half moon" is a tiny thing, and the title, "Smaller than life," seems to fit it. Maybe the moon looks that size held against a fingertip, or maybe it's a thin sliver in the sky. Either way, it's the kind of sight that might invite wonder.
But the speaker can't stay there. "All my thoughts / concern money." The line breaks make the admission feel flat and a little embarrassed, as if the speaker has caught themselves missing something beautiful. There's a quiet irony in it: the moon is right there, and the mind is busy with bills and budgets.
The mood is wry and gently rueful. Nothing dramatic happens, and the speaker doesn't scold themselves. They just notice, and the brevity lets that small, honest recognition sit in the open.