The poem sets a financial idea, trading in futures, beside the plain business of feeding yourself. Its "farmers of chance" don't grow anything; they live on luck and speculation, yet they "eat for nothing." The second line sharpens the picture: every man is "intent upon his belly," so appetite seems to drive the whole scene.
The strangest moment is the offer of "a good cuff on the chops." These men are satisfied by what looks like a blow to the face, which suggests they will accept almost any payment, even a small humiliation, as long as they get fed. The closing image of a leopard that "takes heart at a great supper" makes them sound sleek and predatory, but also complacent, full and content.
The speaker seems to watch with dry, sardonic detachment rather than anger. The mood is wry and slightly unsettling: a comic picture of greed and easy gain that quietly asks what these men give up for a full stomach.