I don’t think there is such a thing as a “Shutterstock model.” It’s the photographers who sell their photos to stock photography sites, and when the model signs the release she may well have no idea what it’s going to be used for or if it’s going to appear on a stock photography site.
And I don’t know how else you can characterize a lot of the photoshopping or search for compromising poses that’s going on here other than slut shaming. I mean, the implication seems to be that she can’t complain because she’s really a dirty girl. To me this is like saying that prostitutes can’t be raped, they can only have their services stolen: being willing to pose in a provocative way doesn’t mean that you are OK with those images being used in every possible way (note that this is not a legal argument, and that she was not making a legal argument in her video).
And since people feel that she was posing in a provocative way, would it be OK to photoshop an actual dick into the picture, instead of just a sandwich? Maybe photoshop some semen on her face, too? I mean, she should have known her photograph could have been used any way, right? (I know @jsroberts has addressed this specifically, but for those who are relying on more legal/contractual/practical arguments as opposed to the moral argument, what is the point of differentiation? I also think BK did make it more explicit/suggestive, because I have my doubts the model would have agreed to that shot if someone had placed a phallic prop in front of her mouth like that.)