The action in the teaser is pretty minimal. All we see is Batman tied up in some kind of pit or cave as he's visited by a decidedly furious-looking Superman. Two lines of soldier guards kneel upon Superman's appearance, and he stalks toward the Caped Crusader to remove his mask so the two can properly glower at one another. It's kind of an equally powerful and laughable scene, and it almost seems to take the animosity between Batman and Superman a few steps too far (given that it's a virtual certainty the two end up being friends in this film or another to come).
A commentary at iO9 theorized that the sneak peek shows Batman having Superman "right where he wants him," and that's definitely one fair interpretation. Their point is that Batman is never better than when he's cornered or underestimated (both seem to be the case in this scene), but it's also important to point out that the conflict between these two characters is about roles and ideals as much as fists and superpowers. From what we know about Batman v. Superman, Batman appears to want to expose Superman as a dangerous force that needs to be contained. And if Superman's really tying people up in caves, it's probably not going to make for very good PR against Batman's cause.
The thing is, most don't seem to believe Superman is really tying anyone up in caves. The assumption, at least across the Internet, is that this is all part of a dream sequence—most likely Batman's. As pointed out by Screenrant, this assumption comes in part because Batman's unusual outfit in the scene has been labeled in a toy collection as "Knightmare Batman," prompting the suspicion that Batman is having nightmares when he's in it. That would definitely explain some of the melodrama of the scene, and it also fits in with the idea that Superman might be driving Batman a little crazy in this movie.
This is actually a relatively popular Batman theme that's been referred to as "Descent into Madness" several times in gaming and character art. Typically, as in the game Arkham Knight, the "descent" is about psychological effects of dealing with the Joker, rather than Batman, but it's also an idea that's become attached to Batman in general. Even at Gala Bingo's slot gaming platform, there's a Batman game with a "Descent into Madness" bonus feature that has more to do with the character independently than any outside influences. Essentially, in comic art, video games, and casino gaming, we've seen indications that Batman can be driven kind of nuts by all of the heroic crime fighting he's involved with. That would probably explain why he's having some creepy nightmares about an evil dictator-esque version of Superman.
We probably won't find out until the release of the film what exactly this teaser was meant to indicate (and that's a good thing!). But the prevailing theory is that it's more a demonstration of Batman's increasingly worried mindset toward Superman than any kind of actual action.