I read an amazing allegory of the film [Gravity][1] in [IMDB][2] and I believe every scene in Gravity does symbolizes something.

So at the last of the movie Stone got a radio-connection from Earth. But unfortunately that wasn't from NASA. But from a mere man. Stone requested the man to make his dogs bark. Then Stone also barked with the dogs' sound. So what does it symbolize?


  [1]: http://www.imdb.com/title/tt1454468/
  [2]: http://www.imdb.com/title/tt1454468/board/nest/223856053?d=223856053#223856053