Joss Whedon is filming additional scenes in London and overseeing post-production for the Justice League movie as Zack Snyder stepped away to deal with a personal issue.
A first batch of Justice League reshoot set images hinted at a Wonder Woman movie connection, and now a second batch of Justice League reshoot set images has hit the net possibly hinting at the Justice League homebase, the Watchtower.
Another possibility is that it could be the Hall of Justice; however, the Hall of Justice was basically featured in an episode of The Flash, so I'm guessing we won't be seeing the Hall of Justice in the Justice League movie.
In the comics, the Watchtower is a satellite that the Justice League operates out of and is their headquarters.
"Justice League" has a November 17, 2017 release directed by Zack Snyder starring Ben Affleck as Batman, Henry Cavill as Superman, Gal Gadot as Wonder Woman, Jason Momoa as Aquaman, Ezra Miller as The Flash, Ray Fisher as Cyborg, J.K. Simmons as Commissioner Gordon and Willem Dafoe an Atlantean, Nuidis Vulko.
Fueled by his restored faith in humanity and inspired by Superman’s selfless act, Bruce Wayne enlists the help of his newfound ally, Diana Prince, to face an even greater enemy. Together, Batman and Wonder Woman work quickly to find and recruit a team of metahumans to stand against this newly awakened threat. But despite the formation of this unprecedented league of heroes—Batman, Wonder Woman, Aquaman, Cyborg and The Flash—it may already be too late to save the planet from an assault of catastrophic proportions.