Faded Photograph is a no longer obtainable in-game easter egg that can be sold or traded between players, a quest item obtained while doing the Linken quest line. When you examine the item it will display a picture of two gnomes in front of Stormwind, a male dressed as Link and a female dressed as Zelda from the Legend of Zelda series of videogames. Many of these were simply discarded and the few that remain are sought after as a novelty and now fetch a premium since this item is considered an easter egg.
Faded Photograph was found in Un'Goro Crater inside A Small Pack at the bottom of one of the lakes [63, 68]. In order to obtain the pack, you had to find a wrecked raft on the shore of the same lake, which would have started the quest  . This will then have allowed you to obtain the small pack.