Barbie Doll

"Her good nature wore out like a fan belt."

This quote is an example of a simile.  I had to look up what a fan belt was, and the dictionary defined it as a part of the engine that turns the fan for drawing cool air through the radiator.   I'm guessing the author used this comparison to show that her good nature wore out quickly, and it was done for good.  The rest of the poem describes a barbie doll at some points and an actual human at others.  The author used the phrases "healthy, tested intelligent" and "abundant sexual drive and manual dexterity" to represent the human-like characteristics.  The poem also demonstrates a person going through puberty as her classmates made fun of her for her fat nose and thick legs.  She was told by others just to ignore the bullying, but she could not take it anymore.  "Her good nature" and going along with everything was done because she was tired of being bullied.  "Barbie Doll" ends with an example of irony because everyone says she looks pretty in the casket when she was made fun of in her life for not being pretty.