In this poem, Clifton pits a powerful (greater) dream self against her everyday self. She emphasizes the weakness and smallness of the this everyday self by using a lower-case "i" to describe it. This literary device of having a word function visually in a poem is called a calligram.
Clifton uses imagery, or description using the five senses (i.e., sight, sound, taste, smell, and touch) to describe her greater self. This self has an "extra" finger that "whirls" in a "gyre"—or circle of rage. We can visualize that finger: a shaking finger is what we associate with a parent or a teacher, adding a sense of authority to the greater self. Clifton continues to employ imagery to describe the intimidating presence of this greater self: she twists "wild" hair, has "wild" eyes that spark, and she screams.
Anaphora, or using the first word repeatedly at the beginning of successive lines, comes into play with the "and"s that repeat three times in a row near the end of the poem.
Clifton uses alliteration in the repeated "w" sounds throughout the poem that replicate the blowing sound of wind and, hence, the sound of the greater self. Finally, by using the title as both title and first line, the body of the poem appears to begin "in media res," or in the middle of the action.