Well, I'm not sure about that. The top of my bowl is the top-half of a doughnut if you will: it really does not seem to have an edge. At what point does an "edge" appear?
he says that a bootle has an edge (~3'40).
A sphere does not have an "inner surface", it has just one surface. So does a potato. If you go from sphere to potato to bowl, when does an edge appear and does it have to appear, is my question.
The inside and outside of a bottle is just by convention. Usually you would say something is inside the bottle if it is past the opening. (As he says in the video.)
So your example with the bowl-shaped "sphere" is correct. There's no clear limit when a bottle has an inside and an outside.