What literary device uses vivid comparison to express something non-literal?

The correct answer is metaphor, as it is a literary device that creates a vivid comparison between two unlike things to highlight a particular quality or aspect of one of them, effectively expressing something non-literal. Unlike similes, which use "like" or "as" to make comparisons, metaphors assert that one thing is another, thereby conveying meaning in a powerful and imaginative way. For example, saying "Time is a thief" implies that time steals moments from our lives without literally suggesting that time is an actual thief.

The other options lack the specific mechanism of creating non-literal comparisons. Rhetorical questions engage the audience but do not inherently provide vivid comparisons. Irony involves contradictions between expectations and reality but does not focus on comparisons. Repetition emphasizes ideas or themes but is not a tool for making comparisons. Thus, metaphor distinctly captures the essence of making vivid, non-literal connections in language.