Making the viewers/audience feel like they know or have some connection to the actress (or actor) makes what's effectively porn more rewarding for a lot of people. It's like a more mild form of the difference between looking at boobs on the internet vs your girlfriend sending you nudes (the latter being considered the superior product by most people). Pretty much every porn actress has a twitter/insta/snapchat they use to share mundane stuff in (often in addition to NSFW content). Celebrities in all industries (not just porn) do it too for the same reason. They want to "connect with their fans". Ocean Spray features its farmers on the back of its juice bottles for the same reason. People prefer a product (be that porn, music or a hipster beer) when they feel like they have a personal connection (genuine or not) to the people making it. Of course there's always a risk you rub the customers the wrong way.