I take that to mean keeping the glove more in front of her. Eliminating or at least lessening the amount of swim she has with her glove arm.
My opinion is you want no swim at all, and I've never seen anyone say some level of swim isn't a big deal...but maybe I just haven't watched enough videos. I guess it would depend on what point in the act of swimming that it meets a person's definition of swim. I tell mine "the glove goes up, the glove comes down." I was taught the glove should be at 2:00 when the ball is at 12:00, and should be at 3:00 when the glove arm is at 10:00. I believe that's Sarah Pauley in armwhip's shared video. If you do some quick pauses, you'll see she hits those exact positions during the motion.
Some people never raise the glove arm above 3:00, and I don't know enough about mechanics to say what does or doesn't happen between 3:00 and 2:00 to make one better than the other, or if it's just preference or for timing.