Much of the video is dedicated to the previous films, shown in release order, but once we get through the story we know, we're given a look at what is to come, and what we see creates many more questions than answers. Let's take a look at everything new that we have and try figure out where it fits in the puzzle.
Rey and Company Approach A City
The first thing we see is Rey and the rest of our heroes approaching some sort of population center on a desert planet. This looks to be the same place where Rey does the awesome jump over a TIE Fighter from the first trailer. Whatever's going on with these people, it all looks pretty positive, people are flying kites in the air. If I didn't know better, I'd think this could be a shot from the very end of the movie, with our heroes returning to a celebration after being victorious, but that seems unlikely.
Following the first new shot we shift from the desert setting to a jungle environment for a shot of Carrie Fisher, who will still be a major part of Star Wars: The Rise of Skywalker. Based on the concept art of Rise of Skywalker that was revealed at Start Wars Celebration, this shot is likely from very early in the movie. We know that what's left of the Resistance will be taking refuge on a jungle planet of some kind.
Next, we see a collection of X-Wings and other Resistance ships hyperspace jumping into the frame. They look to be getting ready for a fight. It's only a brief look, but when juxtaposed with what we see next, it shows just how small the Resistance might be compared to the First Order.
Star Destroyer Army
Star Destroyers flying in formation as far as the eye can see. When the Rebel Alliance or the Resistance has taken on their foes in the previous Star Wars films, we've always seen our heroes look like they're at least a match for the bad guys. However, these two shots of the spacecrafts on either side is designed to show how utterly outgunned the Resistance truly is.
Finn and Jannah
The next image we get is our best look yet at Jannah, the brand new character played by Naomi Ackie. She and Finn are looking at something that they don't like. Quite possibly it's the army of Star Destroyers that we saw in the previous shot. The weather outside the ship they're in looks to be the same as what we see surrounding the Star Destroyers.
C-3PO With Red Eyes
Here is one of the more curious images of the collection. C-3PO with red eyes. Red is always the color of the Dark Side of the Force, so the implication here is not good. Has C-3PO had his programming invaded by something hostile? Is he even C-3PO anymore in this moment? Does Palpatine return by downloading his consciousness into the droid? I mean, probably not that last one, but who knows. Maybe this isn't actually 3PO, but another protocol droid that is just the same color.
Another Giant Laser
It just wouldn't be a Star Wars movie if somebody wasn't attacking a planet with a giant laser. While this one doesn't appear to be a Death Star size blast, though it's hard to tell. Either way, it's still doing more than a little destruction directly to a planet. Star Wars: The Last Jedi introduced the idea that Death Star technology could be miniaturized, so this could certainly be a smaller weapon operating on the same basic principle. Or maybe we're getting our fourth Death Star is six films. It's like poetry...
Rey Throwing Her Lightsaber
While this moment comes later in the footage, it's likely from early in the film, because we see Rey in the same jungle environment where we know the movie is going to start. Rey is seen throwing her lightsaber at what appears to be a training remote similar to the one that we saw Luke Skywalker using in the original Star Wars: A New Hope. The one thing of note here is that Rey looks angry, something that might factor in to a moment we see later.
He's walking with purpose and looks ready to hurt somebody. Where is he heading? Quite possibly to his final confrontation with Rey, which we get to see a moment of in the very next shot.
Rey Vs. Ren
Daisy Ridley and others have spoken in general terms about the big lightsaber battle that Rey and Kylo Ren will have in Star Wars: The Rise of Skywalker. Here we get to actually see some of it. The two will face off on what appears to be the ruin of the Death Star from Return of the Jedi. They're surrounded by water and the battle looks to be as epic as has been teased. Of course, while this might be the final battle, it's not the final part of this new footage.
Dark Side Rey
Of course, they leave us with an image that will likely have fans talking right up until Star Wars: The Rise of Skywalker arrives in December. Rey appears to have gone full Sith here, complete with black clothes and a red lightsaber. This one has an interesting new twist, however, as it is hinged in the middle, allowing it work as a Darth Maul style staff or as two blades working side-by-side.
The question of how this moment fits in the story is a big one. Nothing else, besides perhaps Rey's apparent anger in the earlier shot, hints at any sort of Dark Side turn for the character, and they already teased that in the trailer for The Last Jedi without going anywhere with it.
Could this be a vision that Rey has of a potential future, similar to the one Luke Skywalker had in The Empire Strikes Back? Has Rey been cloned and is there a Sith version that has been raised by the Emperor this whole time? We hear his voice in the footage just before this moment.
On the other hand, some of this moment does make sense. I can't be the only one who has believed since the beginning that Rey would end up with a Darth Maul style lightsaber. The fact that she's trained to fight with a staff would seem to fit. Perhaps, if, as many have suggested, the future of the Star Wars universe is not Jedi or Sith, but something else, this is what that will look like. Maybe Rey is no less the hero here, she just looks like a badass.
If past is prologue, then tickets for Star Wars: The Rise of Skywalker will be going on sale sometime in the next couple months, and a new trailer will be released when that happens. Maybe some, but certainly not all, of our questions will be answered then.