Serious, Heavily Allegorical
Tan uses a lot of implausible stories to make her point—remember that duck that stretched its neck and became a swan? (If you don't, head on over to our "Symbols" discussion.)
These stories are told by the mothers to explain concepts to their daughters, but they're also there to help the reader to understand the hopes and fears of the characters.
Each narrative voice is also deeply serious. But that makes sense—the topics that the narrators talk about aren't exactly lighthearted. There's a lot at stake in every chapter: daughters making the same mistakes their mothers made, feelings of resentment, feelings of inadequacy, etc. Especially in the stories that the mothers tell, the tone is very serious, because the mothers are conveying messages and lessons that they feel are essential for their daughters to learn in order to live happy lives, and make the mothers’ sacrifices worthwhile.