No Food Sign in a Restaurant 禁止食物的餐廳（？）

So frustrated to see a sign of "No Food" at the cashier of a restaurant. What is this restaurant serving then? The Chinese words on the same sign is telling the right message though - No outside food should be brought in.

如果不懂華文，看到這個貼在某餐廳收銀處的"No Food"告示，相信會很困惑吧？