First, her bent Superstar style arms--most Malibu dolls have straight arms.
Second, her legs are a soft rubbery plastic instead of hard plastic. (They still don't bend at the knee, however.)
Third, her facial screening is a little darker around the eye lids and brows.
You can see a few more photos on Flickr, and if you like, you can compare them to a straight-arm version here.