Well, it not might be Imperius exactly, but something like it. If you want someone to actually do something with no questions asked, then you use Imperius in a way so that they don't even realise they're doing it, or they don't mind one bit. But Imperius can also be cast so that they person knows that they're doing something that they don't want to do, or that goes against their will. That's the type of Imperius that's used for punishment.

She's not a teacher but, you know, she might think she's as important as one. Maybe even more important.