Over the Shoulder

http://static.tvtropes.org/pmwiki/pub/images/vertigo15.jpg

An Over the Shoulder shot is one of the most common shots in film and television. It frames a dialog speaker with the shoulder and back of the head of the character being spoken to. Along with the Medium Two-Shot, it is one component of the Shot Reverse Shot. A classic tactic for Double Vision. Sometimes used as a variant of The Faceless.

The video game trope Always Over the Shoulder is named for this.
http://tvtropes.org/pmwiki/pmwiki.php/Main/OverTheShoulder