Ahch-To is a peaceful place. So different from Jakku. Even the winds and the swoosh of the waves are somehow peaceful. But Rey doesn't feel that way. She feels restless, worries about the friends she has left behind. Her thoughts are with Finn. She got the message that he has awoken, but hasn't talked to him in person. Is he really okay?
She shouldn't have so much to ponder. But her training with Luke isn't quite occupying her time. She's still wondering why he's training her at all. His reluctance is obvious. She thinks he even fears to train her. Only when they are meditating together she feels he's balanced. And they are meditating a lot.
Her musing during the day is one thing. But the nights are worse. Because at night the dreams are coming. Dreams about him. Kylo Ren. It seems all her dreams belong to him.
In that dreams he promises her, he will come for her. Repeats his offer to teach her. Tells her she belongs to him, the Dark Side. And she believes him. He won't rest until she's in his hands. She can't do a thing about it. Therefore she waits and meditates with Luke to prepare herself.
When she watches the little inconsiderable shuttle cutting through the clouds, she knows the time of waiting is over. As is the peace on Ahch-To. He has found them.
Rey runs back from the green hills. Back to the huts that are the remains of the First Jedi Temple. To the home of the last Jedi.