Migraines can cause reversal of vision phenomenon when a person sees everything upside down. In such cases, after migraine attack stops normal vision comes back.
Strangely, for human brain it's more difficult to digest the image of a person flipped vertically, rather than the image where the face stays intact while the head and the rest of the body are flipped vertically. No matter how unusual such edit looks the person on the right is usually more recognizable than his unedited copy on the left.
Photoshop celebrities and politicians upside down while their face stays intact, as in this example (by Mundo).
Please include celebrity names in your entry titles.
Thanks to Kellie for the contest concept.