It is the happiest spot on the face of the planet.
While there are some humorous accounts of photobombing, this one feels more like it should be put on a show about haunting images. It is very usual practice to take a number of tries at group photographs in order to guarantee that everyone is pleased with the end result and that they portray themselves in the best possible light.
While it is to be anticipated that a random observer will be captured in a group shot, nobody predicts the arrival of a strange individual who suddenly vanishes after the photo is taken. It is not clear how he was able to sneak into the picture without anybody noticing his presence; this is something that continues to be a mystery. It seems that the person who originally posted the question did not respond to any of these questions.
