During the Giants game, Olsen did a replay analysis on a throw. He showed that Dallas ran a combination route with one deep guy and one short route. When the defender stepped up, Dak went deep. A lot of the other analysis videos show Dallas running these layered patterns.
I wonder if the offense changed or if Dak just got more comfortable with the deep throws. To his credit, these deep throws are frequently covered 1 on 1 and he is just putting the ball right where it has to be.
The offense is definitely much improved since the beginning of the season. Some of it is play design, like the fast motion. Some of it is Dak using his feet. I suspect that some of it is just Dak getting more comfortable with the reads.