Here is another point, Rudolph Carnap once said that what is logically possible doesn’t mean that we can think of it. What he is pointing out is that there are things that we just can’t psychologically think about or visualize. This is partially what Kant is talking about. The Phenomena are those things that are possible for us to experience and that we do experience, because they are in agreement with our mental structure. The Noumena are those things that are external to us, but we can’t experience them because they don’t fit in with our mental structure. One of the points is that we look in the mirror and see what we take to be our bodies. Now take it that we somehow jump outside of our mental structures and see things as they are, and see how our bodies look at it as the noumena, then would look completely different than what we take it to be.