the twins in black

Was anyone else *really* creeped out by the twins toward the beginning of the film?  You know, the cackling ones that carried a dead bird.  How could you miss them?  Well, the first time I saw The Reflecting Skin, the twins were the biggest anomaly to me.  I dove into discussions about what the twins meant… but alas I was not able to unearth much.  After another Google search, I still was not able to find commentary on these gals.  So, if anyone has thoughts on what they represent in the film, please post!  Or- perhaps you have found discussion elsewhere… 

Thanks!