Not Just A Pretty Face Meaning

(idiomatic) Something that is more useful, versatile, or intrinsically valuable than might be assumed.

Example: 2002, Leslie Downer, Women of the Pleasure Quarters, ISBN 9780767909723, (Google preview):
  But she was not just a pretty face. She was brilliant, accomplished, powerful, and tough-minded, a woman of burning passions.
2003 Jan. 19, Abi Daruvalla, "Not Just a Pretty Face," Time (retrieved 2 May 2014):
  Wouter Bos seems too good to be true. He's smart, relaxed and impossibly telegenic, with a knack for coming across as humble and sincere.
2011 Dec. 2, Marc Saltzman, "What to buy a gamer on your gift list," USA Today (retrieved 2 May 2014):
  But it's not just a pretty face. This soccer sim also offers authentic physics — including ball dribbling, passing and scoring, and how the players react to one another — and more than 500 officially licensed clubs, totaling roughly 15,000 players.
2013 Sept. 16, Suzy Menkes, "Fashion Review" In London, the Sexual Language of Flowers," New York Times (retrieved 2 May 2014):
  â€œI was thinking of flowers being not just a pretty face. They produce oxygen and keep us alive,” said the designer backstage.