What is the technique that is used to shape the story One Christmas Eve by Langston Hughes - its about racism?

Langston Hughes uses juxtaposition, a literary

device that places a person, a concept, a place, and idea, or a

theme parallel to another, in order to show the contrast between

the two. Consider the following: Arcie cooks and cleans on

Christmas Eve, does not have a Christmas tree, and has to leave

little Joe with the landlady, while the Missus and her two children

shop on Christmas Eve "for more things for the tree." Arcie and

little Joe have to walk in the snow, whereas the Missus "came near

driving though a stoplight." Noted are but a few examples. Hughes's

short story overflows with lines that invite comparison.