More difficult tricks are worth more points - even if they aren't performed as well as lower point value tricks.
I hear from a lot of people that she didn't look as smooth doing some of her maneuvers - and then watching her perform I hear the judges say something like "Simone Biles is the only woman who can do that vault" and it makes a lot more sense as to why she would get more points for something that isn't as smooth or finished looking as a lower point total vault.