Spider-Man is in the building! At least, that's who we think is in the photo, as it's all rather dark. We'd put money on it being Spidey himself, but we're open to a second opinion, which you can freely provide after seeing it for yourself inside.
The following story contains so many spoilers for Star Wars: The Last Jedi. For real, turn and run if you haven't yet seen the movie, and come back after you have.