Hilton has denied knowing Sizemore, not wanting to be associated with anything tawdry.
As a trained porn sociologist, I know that anyone who is being photographed with a finger in her mouth can't be trusted to pay attention to anything around her. Hilton probably doesn't remember Mikayla, either. (I don't remember Mikayla.)
It is also possible that the three people pictured are not who Vivid says they are. It is just as likely that the three are Bjork, an emaciated Taylor Wane, and Wankus.
The one positive ID is the hand to the left. It is Fate, reminding us we are all going to die.