Whether the Balenciaga casting was thoughtful or cheap gimmickry, I think in the end it was very gimmicky and not necessary. The street casting story was just made up because it sounds very cool. Or so they think.
I've always very much enjoyed Balenciaga castings in the past. I liked how they used Miranda Kerr in the show a couple of seasons ago, mostly because at first I didn't really notice it was Miranda. And in the end they didn't make such a big deal out of it.
For me personally I find the whole, 'let's take a VS model and straighten her hair and bleach her eyebrows' far more gimmicky and manipulative than a model looking like herself. Sasha, Natalia, Karlie, Magdalena, Iris, Lindsey et. al., have distinctive looks that, for the most part, no one tries to camouflage - come on, that is such an ANTM / Tyra Banks move! A caveat, if we are referring to a runway show, of course the model should be styled according to the look of the show, but to me casting and restyling Miranda when she made her Balenciaga debut is as much if not more gimmicky than Miranda's SS2011 appearance, pregnancy and all. I am not saying that she was not qualified for either show, but so were a thousand other girls.
My thing is that when I looked at the SS 2011 Balenciaga show, however which way they got there, with two exceptions, the cast fit the collection and the mood. I guess I am the opposite when it comes to Balenciaga shows and I'll throw in their campaign casting too, because while I won't say that I was blown away by the SS 2011 cast, to me Balenciaga in recent seasons has been awkward girl central and to me this season the disconnect was not as acute, although to be honest I think that the theme allowed for a lower bar when it comes to casting, so while there were some impressive names on the list and you also had the real or faux 'off-the-street' angle and despite the PR spin, this was not a difficult collection / show to cast.
Regarding the exceptions, one minor exception was Jamie Bochert keeping her signature center part in her hair.... oh yeah, it looks like Meisel has the inside track on shooting the SS 2011 campaign. And the model who really did not fit the Balenciaga show was Gisele and that was not because of her looks, but because of her walk - for some reason she decided to do a full-on VS walk, which I thought was hilarious because she did not walk that VS when she was at VS(!) - that chick's hips were swaying and that pony-tail was swinging and I was all, 'you go girl!' and then when I calmed my *** down I realized that that was totally out of sync with what had gone on before.
But as others have pointed out, she has a history with the house.
I guess I will just say, "bless their hearts," and hope that one day they get it right. 
