Re: watching over kids: it's like a regular daycare, so they have dedicated staff to take care of the kids. (Which also means the daycare costs extra, on top of the fees for the co-working space itself.)
When I first started reading the article, I thought they were going to suggest working from home with the child around your legs. Ha! Good luck with that!
On the other hand, I knew a woman with an office right upstairs from the rooms where our children were; she got fed up with the management and moved her daughter to another facility--not very far, but not lunchtime walking distance.
My child is there only two days a week, so I have no issue with not being able to drop in to play during lunch breaks.