The Dallas Cowboys offense undoubtedly got better after Scott Linehan was replaced by Kellen Moore, and it makes you wonder how much Romo and Dak have been held back by the old regime.
On this particular concept, there are two options. The first option is a run play, commonly known as "Buck Sweep". If there is a favorable numbers matchup to the run side (meaning there are more blockers to the run side than there are defenders), then the Cowboys will run the ball. The second option is a pass play. If the Cowboys have a favorable coverage matchup and/or the Cowboys don't have favorable numbers on the run side, they will throw the ball, usually setting it up with a play action (or "run action").
The runningback begins this play split out wide as the 3rd receiver. Quarterback motions him back in and this shows him what coverage the Giants are in. He also is able to identify the defenders responsible for covering his potential pass targets. The defender who is responsible for Amari Cooper (2nd receiver in the slot) is 13 yards off-man. The Giants have also aligned 6 of their 11 defensive players to the playside/run side. This, combined with the alignment of Amari Coopers defender, gives Dak his answer - this will be a pass.
The offensive line to the playside block "Pin and Pull" to sell the Buck Sweep. Runningback crosses the quarterbacks face to show buck sweep. The offensive line to the backside block "B.O.B" or Big On Big. The left tackle who doesn't have a big to block takes the "MDM" or Most Dangerous Man. They ignore the offball linebackers because it favors the Cowboys pass concept if they vacate the middle of the field, which they do.
The quarterback throws an accurate pass on time and in rhythm for a 9 yard completion.