A pretty girl who does'nt like to smile. Usually caused by a traumatic upbringing and/or bad relationships where she was taken for granted. Because of what she's been through, she does'nt realize how truly attractive she is or does'nt consider herself attractive anymore. A prime example of damaged goods.
Guy 1: Why does'nt the cutie that works at Starbucks smile more often? A pretty girl like that should be smiling all the time.
Guy 2: She's a mona lisa, bro.
Guy 1: Well, there's definitely a special place in hell for her ex boyfriends.