What literary term describes an analogy that surprises by comparing seemingly dissimilar objects?

The term that best describes an analogy that surprises by comparing seemingly dissimilar objects is conceit. A conceit is a kind of metaphor that extends over a longer passage or entire work, often drawing a striking parallel between two very different things. This unexpected comparison encourages deeper thought and insight, allowing the reader to see relationships between disparate concepts in a new light. For example, a poet might compare a love affair to a complex mathematical equation to evoke emotions and thoughts about both subjects in an unusual manner.

While metaphor also involves comparison and can lead to surprising insights, it typically operates on a simpler level without the same depth of complexity and elaboration as a conceit. Irony, on the other hand, involves a contrast between expectation and reality, and paradox refers to a statement that contradicts itself but may still reveal a truth. Neither of these terms captures the essence of an extended, surprising comparison established through conceit. Therefore, the uniqueness and depth of a conceit make it the most fitting description for the analogy in question.