Maybe just because she wanted to. It seems like a nice change from desks... I was just thinking about doing that myself, but it's good to know that I'd get detention for it, so I won't.
...My 4th period Geometry teacher is like that. I'm sure she gives at least 15 detentions a day, for just about anything. I'm the only one I know there who's never got a detention, and I'm surprised no one noticed.... She's infamous around our school, everybody hates her, and yet somehow she got our school's Teacher of the Year Award. EVERY single teacher I have is all-around better than her, in both teaching and personality. And she won.
...maybe she got it for giving so many detentions... the principal must've assumed she had bad classes from all of her detentions, and yet still managed to teach us because we make good grades. What he doesn't get is our good grades have nothing to do with her.....