The cuttlefish, like many undersea animals, is quite odd. They belong to the same class as squids and octopi and can rapidly change the color pattern on their bodies. Sometimes, this color change is used to camouflage them against predators and sometimes, it is used to attract a mate.
Cuttlefish populations are male-biased, which means there is a lot of competition between males, especially for access to females. Once a male identifies a female he would like to mate with, he has to convince her. In order to do so, he often displays an impressive array of colors.
However, this display, while impressing the female, also often attracts other males. Basically, the males have to pretend that they haven’t found a female and at the same time, convince her to mate. Tough.
In some cases, a weaker male will display an attractive range of color patterns on one side of his body toward the female and on the other side, a camouflage. Often this camouflage side can be mistaken for a female. The male is then able to mate unobtrusively mate with the female.