I assume Professor Mall Elliot has tenure to get away with such nonsense. Granted, I'm not sure that sort of behavior is covered by tenure, but whenever I heard them say "tenure" on sitcoms, it sounded like an impenetrable shield from getting fired, so... Elliot's fine.
Also, don't feel bad if you thought they were Sarah at first, I am horribly overusing that hairstyle just now.
Anyway, I wanted to do this particular comic because I felt it was easy to forget that Sarah was grown and Nanase shrunk with them separated, and because it was an idea I knew I could get done in advance.
EGSNP has been going up during the day a lot lately, and I figured this was a chance to, at least temporarily, do something about that without feeling like I lost my day off for a week (which I need for my drawing shoulder and for my brain to think good).