If you originate from PVG, they will expect you to have lounge pass, which is printed automatically at check-in. If you connect at PVG, they usually check your incoming flight BP...then you can pass the security guard... When you get to the lounge, show them the incoming flight BP and they will verify your status and you can go in... If you originate from PVG and you dont have a lounge pass, they will call if you look like you dont speak Chinese but they will complain to the agent on the phone as to why you don't have lounge pass. I don't know the exact arrangement but airlines bill (offset) each other for their pax's lounge cost, so they take those lounge pass very seriously

I suspect most non-Asian would not try the noodle bar on the 1st floor but it's quite authentic. I think MU made a very smart move with the noodle station, it's very authentic Shanghainese cooking, with all the proper toppings, but it's actually not costly at all to produce - definitely one of the best airport lounge noodle station.