You choose one of the skins, Sophisticate, Grace, Divine, Babydoll, etc. and then go to a page where you customize the skin. It's meant to be for the purpose of creating a custom skin for Second Life that you would then purchase, natch, but if you like Barbies and Fashion Plates, yeah, just try and not think of the site as a place to just play.
I even got to express my penchant for pubic hair rebellion.
The site says the owners have plans to do a customization service for men too. I hope they do. And I hope they include race and age options and make it at least as customizable for men as it is for women.
Here's a tutorial video. I skipped it and went straight for the good stuff. It's pretty intuitive. Although the video does explain the pricing policy and what to do with the demo and skin inworld, which is helpful.
Does anyone know of anyone else who does customizable skins like this?