She deftly places the palm of her hand on her chin and her elbow on the desk neatly blocking all attempts to 'View the Valley' with the strategicaly placed forearm.
It is a position that can be strongly defended for hours especially when used in conjunction with a swivel chair.
Not to be confused with:
The Cleavage Offence.
Guy 2: "Jeez! No dude. She totally flawed me with The Cleavage Defence."
Guy 1: "Yeah, she's a professional man."