For some reason there are tiny dots throughout the road images on my wife’s nav screen, but not on mine. Of course, we have the same IS model and year. It’s no big deal, but why is that?

 

Route Trace is turned on in her settings, turned off in yours. Not an overly useful feature in my experience. It basically leaves a "breadcrumb trail" of where you've been. Can easily be turned off in your nav settings.