Watch carefully

"watch carefully" is a video that was uploaded to YouTube by Kleanex on May 11, 2007. It features several benign images, along with three poorly-drawn freeze-frames, before showing a jumpscare of an edit of the Mona Lisa as an alien, accompanied by a loud screech. The jumpscare occurs at the 31 second mark.

Link
NOTE: The following video contains a screamer.
 * youtube.com/watch?v=ySAMz6aiQxs