Don't know if it's really her. I know the tattoo can be temporary but I don't think Cameron's arms are that cut or defined. Possibly a morph?
Are you sure that's not Madonna? That does look like the kind of Bra she wore in the early 90's.
Loved Madonnas look in 90s. That sculpted back in Vogue VOGUE
Strike a pose.
original file name does say camerondiaz....and I have seen other pics of her she is buff and has solid cut arms...could very well be cameron