What is the figure of speech in the poem "Harlem"?

Langston Hughes employs many examples of figurative language in the poem.  The overwhelming use of imagery, or mental pictures, populate the poem in helping the reader understand the implications of dreams that are not recognized or are deliberately put aside, away from view and silenced from voice.  The questions offered are done so in a series of similes, or comparisons between objects that use the term "like" or "as."  These are seen in questions such as "Does it dry up like a raisin in the sun?"  Another example would be, "Does it fester like a sore?"  Both similes link dreams deferred to conditions that reflect a sense of withdrawal or pain.  In terms of comparing a dream deferred to something of rejection, Hughes employs the simile of "Does it stink like rotten meat?"    The same type of imagery of spoil is seen with the question of "Does it crust and sugar over- like a syrupy sweet?" When Hughes compares it to "a heavy load," one sees that the imagery has turned to weight or burden.  These images conveyed through the figurative language of simile expressions helps to bring forth a series of concepts associated with dreams deferred.