- Driver is always the person on the controls. No matter what anyone else says, driver has the ultimate power of taking things their way.
- Navigator is helping the driver. Navigators can be well versed in the big picture not paying attention to the road, or know the details of the road and help step through the route in an optimal way. In traditional pairing, navigator reviews. In strong-style pairing, navigator controls the high level choices with words.
The difference between a backseat driver and strong-style navigator is consent and trust. The first delivers unwelcome guidance and the latter provides instructions asked for, on a level they are able to and that they find necessary.
And since mob programming relies on strong-style pairing as it's mechanism of connecting the group, imagine having whole car full of backseat drivers... That could be very uncomfortable.