"What sort of photo editing occurs for school photos? I never imagined that was part of the process."
I guess it sort of varies depending on what's wrong with the kid's face. We do a lot more editing than the big school photo companies.
We crop and straighten all the photos. We pop a few zits and fix stray hairs. People can pay for heavier zit popping. The biggest difference between us and the big guys is that we get rid of the glare from the flashes on glasses. Glare on glasses takes the most time of anything we do, and is fairly difficult. I'm getting pretty good at it and having a tablet/pen input device makes it a lot easier. The big companies specifically say on their order forms that they do not retouch glare on glasses. Another thing we do is colour balancing. We colour balance the photos from each photographer's setup for each day so that pictures of siblings will match even if they go to different schools or are photographed by different photographers.
The colour and light levels change dramatically based on where you are shooting. For example if you are in a school gym that is home of the "Red Devils" and there is a huge red logo behind you on the wall, some of the light from the flashes will bounce off of the logo onto the kid making them more red than usual. If the photographer beside you doesn't have the logo behind them, the pictures will have a different colour cast. Then if the younger sibling is goes to school at the home of the "Blue Devils" they will have a different colour cast as well. Shooting in a drama room looks different than shooting in the gym, art room, or cafeteria. Even though the pictures are mostly the same.
We try to control all the variables. It seems to be working for us.