Three short lines, and a whole small scene. Dogs have found something, maybe a smell, a stick, or a scrap of the day, and they "discourse" about it as evening settles. The title, "Confab," is an informal word for a chat, and it fits the tone. The poet treats the dogs' sniffing and barking as a real conversation, serious and absorbed, as if they were neighbors swapping opinions over a fence.
The speaker seems to be an amused, quiet observer rather than a participant. Nothing is said about their feelings directly, but the playful, slightly grand word "discourse" suggests affection and gentle humor. The last line, "into the green evening," widens the view. The talk drifts outward and the light fades, so the moment feels open-ended, as though the conversation could carry on forever. The mood is calm, unhurried, and a little wistful, the kind of ordinary scene that's easy to miss and pleasant to notice.