you have to get all the triumph forks, and then go back to where you got the camera and pull out the triumph forks there. my friend kevin told me how to get it.
On a serious note, on the Wii U version, the photographer on Windfall Island gives you a few tasks after getting the pictobox and looking at his gallery. Once you've completed the tasks, he gives you the Deluxe Pictobox.
yeah it's a sidequest. although on a new game plus run, if you have the normal picto box, i thiiiiink you get it automatically from the start? i got deluxe on my first run though. but i did start w it