Not all twins are identical, as we can see here with Annie-Claude and Marie-Eve. They might have the same eye color, but the shape of those eyes isn't a match. There's a difference in the shape of the mouth as well, although that may just be because Annie-Claude is smiling more.
The resemblance here all comes from the nose, the shape of the face, and the hair. We find ourselves almost wishing that they'd worn their hair the same way just to underline the similarities.