In other cities in China it's possible to check other people's travel history and get them to do facial recognition on their phone. (So you can't just give your friend your phone). Many restaurants would do this before letting customers come in. Worth also saying that the restaurants are only in the last few days opening their doors for sit down customers and so this is a new thing. People are frustrated in downloading another app and jumping throug hoops but also keen to eat inside when outdoors is still chilly.
I guess the point is, the results of the surveillance is done by each other not just by big brother.