Zoo animals are often restrained to live in an environment widely less interesting and less rich than the normal life in the wild. Some zoos have tried to diversify this environment (a little like what may be done sometimes with toddlers).
The Boomer Ball company manufactures gaming balls for animals living indoor and they wanted photos to publicize their products. The London zoo got the award with this photo that most people will find surprising: Kendra, Siberian (Amur) tiger, with its red ball.
Kendra and its red ball