Wow, this poster has me really hyped for the games. It's got a very serious look to it, a stark contrast to the happy kind of look SM gave off. I suppose you can also see that in the updated Alola map.
Lillie holding a Poke Ball was definitely the first thing I noticed as well. My guess is it's for either Nebby or that Alolan Vulpix, or just a sign of things to come in that she will eventually become a trainer in the game... or already is one perhaps?
My boi Hau, looking serious for once? Holy difference Batman.
As for those shadowy figures at the top, they look similar to some of the Aether Foundation researchers, so my guess is that they are new, high-ranking members of Aether, most likely named Admins, and will have something to do with that portal, which looks to be the same dark portal over Poni Island. Wonder what Team Skull's role will be in these games this time around?
This poster's got me feeling like the story will definitely be a bit darker than SM, or at the very least, more serious. With this many potential differences, it's really starting to feel like USUM will have more of an "alternate" story where multiple story elements will be radically different as opposed to an "updated" story like Platinum or Emerald where besides the mascot, the basic storyline from the dual versions was still intact. Now that I don't know what to expect, I am even more excited for these games.