For years, Disney animators had been going back and reusing sequences from past films but it wasn’t really noticed until recently, thanks to sites like youtube. Many called it ‘lazy’ and ‘a lie’ but it should be worth noting that, while the timing and poses were copied, nothing was ever traced verbatim. Now, with advanced technology, animators can have instant feedback on their shots, in the form of pencil tests or play blasts. Back then, this was not the case.
If an animator wanted a pencil test created for their shot, they had to send it off to a shooting house that could capture and transfer it onto tape, which could take up to a week. And if they had to change the timing, they might need to repeat the process. Keeping in mind that budgets and time constraints were strict, this wasn’t always feasible. So animators turned to reusing shots that already had the timing and posing done. Why reinvent the wheel, right?
Everything in this time was still done by hand though. Animators had to redraw the frames with the new characters, Ink and Paint had to paint the new cels, and they had to be shot on new backgrounds. Disney didn’t start using computer technology until The Great Mouse Detective (1986), so while they reused sequences, it was still created by hand.