The narrator, Jing-mei, began performing listlessly because she could not take her mother's overbearing pressure to make her into someone she did not desire to be. Jing-mei had no desire to be a famous musical prodigy. She rebelled against the pressure her mother placed on her. She literally would kick and scream as her mother dragged her to the piano to practice. Jing-mei would then perform listlessly, without any passion for playing the piano. This was Jing-mei's way of rebelling against her mother's forceful nature:
The narrator's mother is a Chinese immigrant who wants her daughter to have the best of both worlds: Chinese tradition and American opportunity. Like many mothers, however, she has a tendency to try to make her daughter into her own image rather than allow her to develop into her own person.
Jing-mei decided she would not allow her mother to change her. This was Jing-mei's way to practice her own independence. Jing-mei did not desire to be a famous Shirley Temple. She had no desire to be a famous musical prodigy. She resisted her mother's controlling features. That is why she chose to perform listlessly--without emotion or passion. She only performed in a ritualistic manner. She had no overwhelming desire to play the piano. She felt that if she performed listlessly, then she would be punishing her mother for forcing her to take piano lessons.
Jing-mei is intelligent. She realizes her mother is pushing her to play the piano so she can compete with Waverly's mother. Waverly is a chess champion with many trophies. Jing-mei's mother desires for her daughter to play the piano and win may trophies such as Waverly has done. Jing-mei realizes she is being used by her mother to compete:
She also understands that her mother is using her to win a competition with her friend Lindo Jong; both women brag about whose daughter is more talented. She is resolved to be true to herself and not take part in such a competition.
Performing listlessly, without spirit or enthusiasm, is Jing-mei's way to get back at her mother for forcing her to be someone she is not. Jing-mei is determined that her mother will not change her into someone she does not desire to be.