Then I think it's the way her hair hangs down to cover half of it, which gives it a much sharper cast. I'm mainly comparing her new image to the pic you have of her in your profile. But going into the game and comparing her old model directly, I think her new body shape looks significantly broader, possibly because of the extra coat layer she's wearing over her kimono. It's hard to express properly, the old Kisayo carried herself like an unsheathed knife, which worked well with how cagey Yaichi had to be dealing with her because of who her father is.Facial structure wasn't changed at all.
Either way, doesn't change my stance that the old Kisayo looked great, while the new one just looks... generic. I know my opinion as a non-Patron means approximately nothing, but I'm still seriously going to miss her when she gets changed.
Then again, if it's an all-new version that's still several months off anyway and will require a restart, I can not worry about it for now and just keep playing the old version.