Pretty sure it's just a pretty good photoshop job. I think Gandalf is from the Isengard fight, and Frodo could very well be from a behind the scenes shot, maybe rewatching a scene on a monitor over someone's shoulder.
Idk when this is from but I have been to a party once where Elijah Wood was DJing, it was a party during SXSW at the WeWork office sometime maybe 2015ish.