This photograph is part of a winning sports photography portfolio because it shows the exact moment before the coach notices he is being dunked with whatever is inside the cooler. This is a traditional celebration when a sports team wins a big game.
The shutter speed is high because all motion is stopped.
Shutter speed is how long of a pause there is between each shutter closing. A faster shutter speed means that motion is captured better.
This could be a key photo, but it also could definitely be set up.
An advanced technique used in this photograph is the use of high shutter speed and also leading lines.