I'm confused. So this is just producing a single photo that is clearer in a middle rectangle and blurrier outside that rectangle?

Of course the extra detail in the middle is nicer, but won't the edge of the "detail rectangle" be extremely obvious and distracting? Like when you zoom into satellite view on Maps and it's clear that there's a blurry area and a sharp area?

I don't understand why you'd ever want these two things combined into a single image. I can understand why you'd want to snap photos with both lenses simultaneously as save them as separate photos, but I don't understand why you'd combine them.