Luke Skywalker will be training Rey in The Last Jedi on the isolated planet Ahch-To, which is where he has been residing for the last several years. The planet is definitely mysterious, considering it was the location of the first Jedi temple, and now, only wild creatures roam there with Luke. His whereabouts and the mysteries of this planet will be explored in The Last Jedi. Here’s an official image from Yahoo! Movies of Rey on Ahch-To.
The image doesn’t really reveal much, but it looks to be the same area that was shown in the trailer where Rey was practicing her lightsaber skills.
I’m fairly certain that this image is taken from a shot earlier in the movie. Her outfit in this image looks to be what she was wearing at the end of The Force Awakens, and it looks like what she will be wearing for most of her time on Ahch-To, with Luke. It seems that later in the movie, though, she will adopt another costume, one that is a darker variant of her Jakku outfit, and she will also let her hair down. I think that shortly before or after she leaves Ahch-To, she will change her outfit into what she will wear for the remainder of the movie.
These images possibly reveal Rey’s early look:
These promo images possibly reveal Rey’s later look: