The first trailer established the premise: aliens invade Earth, soldiers die quickly, one is caught in a time loop until he becomes a better soldier. The second trailer features Tommy Terrific, explaining things to Emily Blunt, and then performing heroic deeds, such as riding a motorcycle and jumping around in a mechanized suit. You'd never know that Blunt's character is actually the superior soldier, a thought that's briefly acknowledged when she declares that she will train Tom.
With the movie due for release on June 6, however, what needs to be sold is that Tom Cruise is the hero in a big-budget sci-action action war movie: fewer gleaming surfaces than last year's Oblivion, better equipped than Steven Spielberg's War of the Worlds, Tom will save humanity, and I think that is made loud and clear in the trailer.