What Happened, Happened is an achievement/trophy available in Escape Dead Island. To unlock this, you need to collect all 86 of the snapshots scattered around the game. They can be found in any order and over multiple playthroughs, as they accumulate each time, so you don't need to go and find them all again each time you play a new game. A snapshot that counts towards these will glow green when you look at it using the camera. If it's out of range, it will be red, so move round until you can focus on it, then take a picture and it will come up as a snapshot. Upon collecting the final one, the achievement/trophy will unlock.
Dead Island Wiki