OK I know this is an old question but I still dont know if its been clarified. Having just stumbled on a picture of it Im fascinated all over again. Has she spoken about it or confirmed any surgery? I know there are various methods from injectables to implants. Maybe padding?
Though I want to point out, her ass doesn't looks that huge in person. I think a lot of her crazy outfits she wears at awards shows have additional padding. Especially the outfit in the first pics.