Inner classes are too difficult for us who are just "beginning", so I shall move this thread. I think there might be an interesting question there, but you really ought to tell us what that question is
You have several classes which implement your interface, with show() methods. You can call all those show() methods,and see their output.
You obviously have a further question, which you haven't yet asked.
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime.