Using a photo editor, two pictures are blended together to create flat image of a head, which is then laminated and submerged in a jar. When the flattened image in inserted into the curved jar, along with the distortion from the water, gives the illusion of a decapitated head in a jar of preserving fluid.

Here’s what you need to make your own:
– Photo editing software
– Large jar
– food colouring
– printer + access to lamination service (local print/copy store

 

Source: Crackajack