In "A Sunset of the City" by Gwendolyn Brooks, the poet primarily uses caesura in the lines you've referenced. Caesura refers to a pause or break within a line of poetry, often found in the middle. This technique adds rhythm and can enhance the emotional impact of the poem.
While elements like alliteration, rhyme scheme, and internal rhyme may also be present, caesura is a defining feature in many of Brooks's works and is particularly notable in this poem.