In the poem below the phrase petals on a wet black bough is an example of what?

The phrase "petals on a wet black bough" from the poem "In a Station of the Metro" by Ezra Pound is an example of imagery, as it creates a vivid mental picture of delicate flower petals contrasting against a dark, rainy background. This image conveys a sense of beauty, fragility, and melancholy in just a few Words.