This is an animated gif of the Terminator smiling. The awkward smile makes this gif hilarious. The Terminator was played by Arnold Schwarzenegger. This is from the second in the series (1991, believe it or not).
This gif of Arnold Schwarzenegger playing in the movie Terminator 2, Judgment Day. You can see Terminator smiling in a very fake and forced way just to please John Connor ( played by Edward Furlong).