In the book: Mia has a quieter nature and chooses not to become attached to people. That isn't to say she isn't opinionated. She's the one who urges Bebe to fight for custody of her baby, May Ling, and she even raises some concerns about Pearl spending so much time with the Richardsons. But there's a sort of subtle passion and quiet wisdom about her demeanour. For instance, when she finds out about Lexie's abortion, she takes a gentler approach to helping her recover, even though Lexie got Pearl wrapped up in the situation.
On the show: On screen, Mia is much more overt with her thoughts and expressions. She vehemently tells Bebe to get May Ling back, doesn't bite her tongue as much when it comes to calling out Elena, and slams Lexie for using Pearl's name on the abortion papers. She's also very explicit about class and racial divisions.
Part of this likely has to do with Mia being Black. Ng never discloses her race in the book, leaving it open for interpretation. But with a clear and distinct identity, it's easier to have Mia's character take a particular stance on how she interacts with the Shaker Heights residents, specifically Elena. But that's the thing — it's easy. Rather than allowing viewers to detect the fray, the series spells everything out. For those who like an unambiguous tussle, this approach is effective. But for those who enjoy discerning complexities that simmer rather than erupt, Mia's disposition feels a bit insipid. The gist of it, however, is completely justified.
On the show, Mia is also more involved with people. Case in point: she gets drunk with Elena, which she doesn't do in the book (probably because it just seems too out of character and even a little unnecessary). Additionally, Mia sleeps with her Lucky Palace restaurant manager, even though Ng suggests she's asexual in the novel. Although the sex scene is meant to serve as a foil to Elena, who literally schedules intercourse with her husband, it almost mars the mystery of Mia. A woman who can have sex without getting attached? Even in the '90s that wasn't very cryptic or groundbreaking, but a woman who doesn't partake in sexual relations nor desires them? That's someone with a different kind of power worth exploring.