This picture is called 'A Thousand Years' by Damien Hirst and it represents the cycle of life.
In the white box with holes are thousands of maggots, when the maggots turn into flies, they fly through the hole in the box to the cows head on the other side of the container. The flies feast on the head and also a bowl of sugar cubes in the corner [for dessert ;)]. The flies buzzing around toward the top of the box are brutality killed by the 'insect-o-cutor'. Those lucky enough to survive continue with their ferocious cycle.