Mike Stone's short poem looks like a haiku and borrows its calm, observant tone, but it ends on a joke. The speaker sees three chrysanthemums lined up in a "buttery row," and the colour and softness of the flowers suggest butter. Then comes the twist: "What lost vegan luck!" Butter is dairy, so a vegan would never want it. The flowers look like something the speaker can't have, and the "luck" of finding it is wasted.
The title, "Chance," points to the accident of the moment: the flowers just happen to resemble butter. The speaker seems amused rather than upset, mock-mourning a pleasure that doesn't apply to them. The mood is light, wry and playful. The poem takes a quiet, pretty scene and treats it with a shrug and a grin, which makes the small, odd observation stick in your mind.