The image above shows us the entire contents of a firetruck in Geneva, Switzerland, sorted and categorized, including the crew. This is an example of a very popular Instagram meme called knolling.
So knolling is a type of flat-lay photography, where different objects are arranged at 90-degree angles from each other, then photographed from above. The look is symmetrical and pleasing to the eye and allows people to see a variety of objects in a single picture; perfect for demonstrating equipment or an inventory, for example. The process has been further popularized through LEGO, where builders carefully arranged their bricks by shape, style and color before getting to work on construction.
Knolling of emergency service vehicles is also known as the Tetris Challenge. Here is a Boxer MRAV of the Royal Netherlands Army.
Considering how well-equipped modern emergency services are, a glimpse of what they have is intriguing, even if we don't understand most of what we are seeing. Once a few crews did this, everyone wanted to get involved. Below is a police van in Neuchâtel, Switzerland. We assume that they enlisted someone innocent to play the part of an arrestee.
You can see 30 ranked images of emergency service knolling at Bored Panda. You can also explore more through the hashtag #tetrischallenge at Instagram.