Bingo. That is likely the biggest reason for how much effort they put into it. Also...That, or just to make the movie seem more exciting in the trailers.
I am pretty sure that scene is going to be the start of the movie. It's likely after the opening splash credits, it will zoom in on Batman overlooking the destroyed landscape with alien ships looming (the image linked recently). He goes down and meets with what is left of free humanity, getting ready for the coming invasion of Superman, his Super-Soldiers and alien allies (the bug guys). A big battle commences and Batman is the last one standing, with the Super-Soldiers swarming him and taking him down. They drag him downstairs, hang him up by his hands, and then that scene will happen where Superman shows up, the soldiers all bow to him, he takes off Batmans mask, looks at him, then is about to incinerate him with his eye beam, then Bruce will wake up in a cold sweat. It's supposed to set the tone of why Batman fears / hates Superman throughout the rest of the movie by showing us what he believes will happen.