The head is slightly tilted forward.

Disapproval The person has a critical, judgmental attitude about the other person or the current topic.
“I think nothing of it!”

or Greeting The person nods and greets with a slight bow.
“Hello!”

Explanation
How long the head is tilted and the context provide changes the meaning of this gesture: the longer the stare, the more disapproval. A critical look over the reading glasses, reminds of a teacher and may be intimidating.

Categories face,

This is one out of 63 gestures from the body language trainer.