SHAPESHIFTERNoun. Definition-Someone who takes pictures on myspace/facebook so they look really attractive. Unfortunately when you meet up with them they look nothing like their pictures, The right angle and good lighting is much more powerful then any magic I know of.
Best defense. Don't apologize, run away screaming "tis a witch! tis a witch!" She knew exactly what she was doing.
Best offense. When drunkenly finding someone the next day after a party (see THAT GIRL for how to find someone after a drunken hookup. ) make sure to look at pictures their friends uploaded instead of the few carefully picked out profile pics she did.