I came across this picture on Instagram that was posted 2 days ago by user @Schack_attack. The photo was taken at the Pullman Train Yard, the same location where we saw the pictures of the Capitol cars.
Since we see miners in the billboard, it looks like it has something to do with District 12. What do you guys think?
Oops, sorry you missed the photo! Lionsgate requested us to delete it to avoid spoilers.