This lecture was looking at the differences and similatiries between American and Japanese animation.
Disney made a breakthrough with Bambi when they introduced the 'moving background' by having 2 or 3 layers of animation to give the cartoons a sense of 3 dimension. Something that was picked up on and used by Japanese animation afterwards with anime such as My Neighbour Totoro.
After that more innovations were made in the field of animation, such as the 'tear drop body' shape in early Pixar cartoons allowing more natural and flexible movements, and motion blur. However despite these innovations, animations as a medium did not 'improve'. Stories, characters, and popularity were not effected, just because these things were new does not mean they are neccessarily better.
What made animation better was the way they used these products to help make the characters realistic in different ways, now animators could bring objects to life a lot easier than before and translate tough emotions into them. Without these breakthroughs Pixar could not have made this: