Another tough one to add to your list of accomplishments. We struggled a little bit, but we managed to figure it out eventually. Probably the most obvious one is Belle's nail color. In the first image she doesn't appear to be wearing any nail polish. In the second image her nails are painted a burnt orange color.
Next one up is her hair. Belle is looking slightly tidier in the first image, with just one strand of hair out of place. In the second image, things have gotten a little messy with two strands now in the picture. The third one was the most difficult to find. If you notice the wall behind the pillar to the left of the picture, you'll see there is detailing in the first picture that isn't there in the second.