An NBA Point Guard has to be a floor leader. On offense, the PG typically brings the ball up after COP or at least initiates the offense. He calls the plays to be run, or relays the play called from the bench to his teammates. He has ownership of dictating the tempo. He must see mismatches, particularly coming out of transition, where the cross-matches presented advantages for the offense and then get the ball to the player with the advantage. The advantage may be size but it can also be someone in position to score with his man out of position. The PG must know the game clock, shot clock and score at all times. He must direct traffic when needed and when he runs the break, he must be able to judge where the best scoring option is very quickly, and if there is one. He must make a passing decision on the break by the time he gets to the FT line.
Those are just a few of the key elements for an NBA PG on offense. Mason has some execution issues as a PG.