Pedestrian Behavior

You see it all the time.  We saw it tonight.  You motion in your car for a pedestrian, who wants to jaywalk, to go ahead and cross the street.  The pedestrian nods, waves, and breaks into a quick trot that lasts about 4-5 step and then they resume walking until they cross the street.  I wonder aloud: why don't they just keep on trotting or simply walk the whole time? 

I suspect the pedestrian wants convey appreciation by showing some hustle, or they may want to avoid the driver's horn for doddling across the street.  Regardless, it is humorous to observe.