Answer: The right answer is the Rich imagery that appeals to the readers’ senses.
Explanation: Just to elaborate a little on the answer, it can be added that by using a descriptive language—pavement sparkling with sunlight, pigeons fluttering off the curb and nodding over a profusion of bread crumbs—the poet Billy Collins is trying to appeal to the reader's senses (sound, sight, and even smell) with the goal of recreating the scene in a clear and persuasive way. The speaker is listening to music and he is in good spirits, and he wants to share his upbeat mood with the reader.