The others use seafood sauce for the McShrimp, salsa for the McShrimp Chicken Burger and McSpicy Chicken Thigh Burger, custard, pickle and ketchup for the Big Mac and custard burgers, and barbecue sauce for the Fresh Veggie Footed Zun Beef Burger.
As a reminder to the owner, these sauces are specially supplied by the supplier according to the requirements of McDonald's, and the ones we buy in the supermarket are just similar in flavor.