According to John Gilroy, talking in an interview with Yahoo Movies, the reshoots — which were ordered last summer — “gave you the film that you see today,” adding that “there were scenes that were added at the beginning and fleshed out [because] we wanted to make more of the other characters.”
Among the scenes added? “The scene with Cassian’s introduction with the spy, Bodhi traipsing through Jedha on his way to see Saw — these are things that were added.” Also specifically named was the introduction of the adult Jyn Erso (Felicity Jones): “How we set her up and her escape from the transporter, that was all done to set up the story better,” revealed Gilroy.
Another editor on the feature, Colin Goudie, continued, “The point with the opening scenes that John was just describing was that the introductions in the opening scene, in the prologue, was always the same. Jyn’s just a little girl, so when you see her as an adult, what you saw initially was her in a meeting. That’s not a nice introduction. So having her in prison and then a prison breakout, with Cassian on a mission … everybody was a bit more ballsy, or a bit more exciting, and a bit more interesting.”
Neither Gilroy nor Goudie went into as much detail about the movie’s finale, although Gilroy said that “it changed quite a bit. … I don’t want to go into too much detail about what had been there before, but it was different. We moved some of the things that our heroes did; they were different in the original than they were as it was conceived.”