Answer: To show that it is a metaphor and not literal
Explanation:
''Talk the hind legs of a donkey'' is having a meaning ''making a donkey sit down on its rear end'' which is not something that donkeys do naturally. It is used when we are describing a person who is talking to much. This phrase has its origins in Ireland.
In this case, the author is considering that person can talk much about her tales.
Manuel I just read the book one of them
1. Gerund 2. Prepositional
The two characters motivations are
Personification, America is an object, not a person, yet it is singing, which is a person like quality.