More from the Jackson interview (the first part of which is here)...
"Pinocchio" was the last picture I worked on that was done so strictly under Walt's guidance. All during the thirties it was that way. Then he backed off and began throwing more responsiblity to the rest of us. He figured we should know our business well enough to help him make pictures instead of being extra fingers on his hand.
And it's my personal opinion that this accounts a great deal for some of the difference that you see in the spirit and the heart that you see in the pictures during the thirties. That gradually, it got a little less evident until it got to the point, in my estimation, where the Disney pictures became superb techically, but a little lacking in a joyous creative spirit you'll find in those early pictures. As time went on, it was more and more diluted by the influence of others...
You mentioned the development of the personality in the characters. This is something that Walt leaned on hard, right from the start. Back in the very beginning, I was there on the first Mickey. But even then, that was Walt's big drive, but the artists were mostly cartoon guys who drew funny pictures to laugh at, more than later on. Later on, Walt expected good draftsmen.
But the crudeness of the medium worked against us too, because there were just black and white movies in 1928. You youngsters haven't experienced an old projector in a movie theatre with a kind of a yellow image that was flickering, and all that made it so that you had to make a very crude drawing, done very broadly.
The refinement that was in drawings later on would only have confused things in those early days. If you had photographed a bunch of cels from "Sleeping Beauty," for instance, and reproduced them with the techniques we had in the early thirties, you would have had a mismash on the screen. The audience wouldn't have known what they were looking at, because the reproduction and the projection were so bad.
So all these things are involved with the fact that the personalities began to come across better later on, along with the fact that we were all learning. We were growing along with the business. Walt himself was a youngster when I went there. It's not my recollection that there was any greater emphasis on going after the personality and the believability of the characters in "Pinocchio" than there was in the early Mickeys. It was just that we were a little more capable of it then. There was just as much drive and emphasis on it way back, we just didn't know how to do it.
It was the uppermost thing, and it all came about because Walt wanted to make the cartoon characters believable to the audience. Right from the start, he didn't want them to be just something moving around on the screen and doing funny things. He wanted the audience to care what happened to the characters, and to believe them as real beings, not just as a bunch of funny drawings.