I first came across her a few days ago at Stereogum in this image from their Serge Gainsbourg tribute concert coverage:
As in 'Who's that sitting behind Beck?'
It turns out that she's Charlotte K M, girlfriend and sometime musical partner of Sean Lennon, and also a top model in her own right. This tumblr page has the basic evidence that she's one of those truly spooky beauties who never takes a bad picture and who can look like almost anything while always looking exactly like herself. When the camera loves you in that very specific, strong way (you're Audrey Hep. or Milla Jov. say), Hollywood and fame more generally usually comes knocking (and ordinary mortals feel like killing themselves!). It'll be interesting to see whether that happens in this case. At any rate, here are a couple of nice images of CKM in casual musician mode:
Reading around, CKM has done a few silly interviews (leading some people to claim she's vapid and a calculating dater/climber, etc.), but otherwise she seems to have impressed people with her smarts and general sensibility. We'll see.