Answer:
Parentheses are used to show what the speaker of the poem is thinking.
Step-by-step explanation:
In the poem "The Buttonhook" we are introduced to a girl who is the speaker of the poem. This girl begins to describe things that she is seeing while walking through a region. This girl is an immigrant so everything looks new and exciting to her. In addition, she begins to associate what she sees with information and situations that she has witnessed or heard about.
During the girl's descriptions, we are introduced to her thoughts. These thoughts are placed within parentheses.