Answer:
Espaillat uses structure to develop the theme that grief affects people greatly by using an A, B, A, B poem structure until the last two lines that go A, A. This 'flatlining' either means that the author's mother has become emotionally numb do to her grief and repititive working coping mechanism or she has died due to this, therefore her death being represented by an A, A rhythm.
Step-by-step explanation:
The structure shows (especially at the last two lines) an example of grief and its affects through her mother. She's 'alive' either metaphorically or physically and then 'deceased' at the end metaphorically or physically.
Hope this is understandable and helpful!