What is the metaphor in "Two Kinds" by Amy Tan?

Let us remind ourselves that a metaphor is a piece of
figurative language that compares one object to something else by asserting a direct
comparison, without using the words "like" or "as." The most important metaphor in this
story about the conflict between a mother and her daughter actually comes towards the
end of the text, when Jing-Mei's mother gives the piano to her daughter in spite of the
many disappointments she has caused her mother. Having asserted her "right" to "fall
short of expectations," Jing-Mei sees this gift as a sign of acceptance of who she is
and who she has become from a mother who has always appeared to want her to be more than
she is. Note how the piano is described:

readability="10">

And after that, every time I saw it in my
parents' living room, standign in front of the bay windows, it made me feel proud, as if
it were a shiny trophy I had won
back.

Now how the piano is
described as a "shiny trophy." Jing-Mei obviously feels that she can use this metaphor
to describe the piano this way because she believes she has won this trophy on her own
terms and has not conformed to her mother's crippling expectations for
her.