After party maybe? Idk why they're be in costume though.
Gotta be on set. Messing with the sound guys stuff.
Can't tell if serious, but if so, sound guys on film sets definitely don't have turntables.
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.
