What is a phrase?
a. a complete sentence
b. a grouping of words that does not have a subject and a verb and can't stand alone.
c. a grouping of words that can stand alone.
d. a subordinate clause that has been written and punctuated as a stand-alone sentence, but does not make sense as a sentence.

the answer is:  

he is voicing feelings shared by all humans regardless of race.

in paul laurence dunbar's poem "we wear the mask," he replicates the words mask and we to emphasize how people in general -not just black americans- hide their true feelings. he suggests the masks cover people's faces and eyes, which are the main parts that display their emotions. he also thinks people's pain conceal behind those masks, so that they cannot see reality and nobody is able to see one another's sorrow.