Don't worry about it. Basically the waiter just walks in and takes a plate. The chef has no idea for what plate. And the waiter is paid (tipped) to serve you. Enjoy all you want and don't worry about it.
Only thing you should know is that dishes are basically preplated. So you will get a full plate, even if all you want is the main part of the course. It's much easier for them to do it this way considering the thousands of meals that they serve.