The tat thing is kind of especially weird to me. Because with the clothes, you could at least sort of argue that you're representing them... sure, it may not be how they looked on that PARTICULAR day, but at least they're covering, not altering. It'd be like if they had a teacher standing by with an overshirt and forced them to put it on if their clothes were deemed inappropriate... just a lot more cowardly, because they're doing it after the fact and thus not giving them a chance to protest or change on their own. It's still wrong, but a lesser wrong.
But the tattoo, they actually changed what the person's actual skin looked like... and not in a transient way like removing a pimple that is only there for a few days and it was just bad luck it happened to be on photo day... this is what her skin's going to look like for the forseeable future, and they changed it. To me, that's more like a big ol, "Your body ITSELF is unacceptable to our standards." And... %$#! that, you've failed as a school if you ever send that message.