They do seem kind of 'intertwined,' almost like they're inseperable. And their behaviour/demeanour is a little bit strange. I agree also, that Ariana looks ill. Cynthia doesn't look too perky either. Both attractive young women who seem to have been affected by the fame bestowed upon them.
On the second clip that pops up, they can barely function in those ludicrous dresses! I don't think Cynthia is creepy and narcissistic though @BelatrixLestrange I just think she just really likes Ariana... I think Ariana likes her too. They're just good mates I think! I have no idea why you - or anyone else is calling them 'narcs.' You don't know them, and they seem nice enough to me.
I wish them well. But yes, they don't look very well. I think it's a bit sad that famous women are made to feel that the only way they can be loved, recognised, and famous, (and stay in work) is to be, and stay thin. I remember Kate Winslet, just after she had her first child, she put on 4-5 stone, and she said she HAS to lose it all, or she will not get any more acting work.
I'm not having a go at Cynthia and Ariana by the way (or anyone who is quite thin,) but I don't feel this is how they normally look. And I don't think they're a healthy weight.