[ImPostingOnHN]

> A large amount of engagement is reading and responding to body language.

I don't follow this assertion – it's possible to be engaged by something that doesn't even have a body. For example: the things currently engaging them in this scenario – their phones (or whatever's on them).

[renjimen]

Engagement being a two way thing between the teacher and student. In this case I was referring to the teacher reading and responding to the student's body language.