As we all know that the Batman Vs Superman Dawn of justice is loosely based on 1986 four-issue comic book miniseries written by Frank Miller. The screenshot on the left is of the Batman: The Dark Knight Returns animated superhero film, an adaptation of the 1986 comic book. In the movie Batman uses a harpoon rifle to go across the Gotham twin towers and not for the kill and in the trailer we see Batman standing on the a tall tower so maybe its for the same purpose. It's just a wild assupmtion. What do you guys think??