I wonder if they’re cheating with that last shot? Do we technically see Rey and Ren in the same frame?
I think it might be Rey’s vision, she asks him in her force vision to help choose where she’s supposed to be, then she wakes up and falls to the ground gasping for air, like in the teaser. Then she dives into the water and climbs out. She then tells Luke what happened and what she thinks she needs to do. Then Luke says, “This is not going to go the way you think!” Which eventually leads to her in front of Snoke frozen in place after defeating some of the red Praetorian guards.
Remember Luke has been down this road before. He saw his friends in Cloud city in his vision too, but Yoda warns him that, “Hard to see, the future is.” Luke is warning Rey, what she sees in her vision, isn’t going to be what actually happens, because the future is always in motion.
That’s what I took from the trailer. I hope this helps.