So looking on Wikipedia Danni Minogue fits some of the clues.
She had a fashion range in Australia and has been the face of fashion week there.
She has had various famous big deals with X factor ect
She was the face of a makeup brand and maybe the biggest clue is she is a judge on the Australian version of the show.
The other popular guess on Twitter is Katherine Jenkins. Apparently she rented her house the the apprentice, one of her childhood crushes was Jason Donovan no links to make up or fashion that I know of.
I'm still inclined to think it's someone we haven't guessed yet/won't know even without the mask on.