Walter's first lesson during the pandemic

Next Monday was his first lesson in the middle of the pandemic. Unfortunately, he taught upper school.
And of course he didn't feel like getting the Kung Flu from one of the bricks!

Fortunately, he had recently invented the iBod, which could transform himself into anyone.
So now he had an idea! He quickly made an appointment with the school principal.
"Mr. Miller, Professor Schmidt is here!" said the secretary to Mr. Miller, the director of the comprehensive school.
"Send him in!" said Miller.
Now the door opened. And entered ...