These photos are using the "Thatcher" effect.
The effect is created by flipping a portrait upside down while keeping the eyes and/or mouth right side up.
The human brain has a difficult time detecting these subtle “local” changes, and the portraits may look normal until you see them flipped.
Try turning your monitor or head to look at these images upside down...CREEPY!
Dutch photographers Anuschka Blommers and Niels Schumm shot this series of photographs for a Dove ad campaign.