The difference between polar a spherical photos is that when you make your polar you don't have to turn it at an 180 degree angle. So that means for your pano you have to turn your photo at a 180 degree angle. When the photos come out your pano looks like you have your own world. But your spherical looks like your trapped in a world.
What makes the finished tiny worlds convincing is the back round. When you make it you out line a circle for the world. For the polar you make the back round black so it gives the effect of a world in space. And for the spherical you make the back round white so you can see the circular shape better. And in the final 2 pano's and spherical's your person usually has a shadow. So when it turns out you person looks more realistic because it has a shadow.