What is the real difference between this and startup companies?
A company isn't a young adult.
Sounds more like cheaper co-working space.
Yeah or like a themed university library. I'm sure this kind of stuff is way cheaper in China, but $5 for a desk and food for a day seems good. Gets you out of the house and interacting with people.
Startup provides you some pay usually (and you're not working for free), these folks are paying for the experience.