At the start of Mimikri, all twenty butterfly tiles are placed face down in the middle of the table in the shape of an rectangle. One of the five picture tiles is then inserted into the special "camera" included in the game; this camera consists of a squarish cardboard device with a mirror standing vertically on the diagonal of the square, along with a cut-out "wing shape" on the bottom of the camera. When a picture tile is inserted underneath the cut-out, the "camera" will create a butterfly from the part visible through the cut-out together with the mirrored wing. Since you can insert square pictures in four directions, each picture can create four butterflies depending on how it's orientated.
Once players see the image of the butterfly created, they now try to find this specific butterfly by turning the tiles face up, one by one, until a player finds the matching butterfly. Since the tiles remain face-up during this time, players have the opportunity to memorize as many cards as possible.
Once a player succeeds, he collects the matching butterfly card and places it face-up in front of him. All other butterfly cards are turned face down again. The next player now exchanges the picture tile, trying to insert the next one in a direction resulting in a butterfly he is able to locate immediately. This is more difficult than it seems as you have to imagine the butterfly just from the picture before inserting it.
The player who collects the most butterfly cards wins.