Developed at ACW the animated sequence in Mary Poppins Returns consisted of a whole other song that never saw the light of day “The Anthropomorphic Zoo”. Jamie Baker, Jim Capobianco and animation production designer Jeff Turley spent quite a bit of time developing the sequence. It was a lot of fun and had some really interesting gags in it. The whole conceit was that the animals were outside the cages and the humans mostly lawyers, bankers, politicians - the usual group we all wish were locked away were the exhibits. All handled with satire and tongue and check jokes, it was a unique and quite a daring concept from the original Mary Poppins book and was actually developed for the original 1964 film but was also abandoned.
Here is a link to an article about the sequence with the music and also some of the storyboards done by Jamie and Jim. https://www.usatoday.com/story/life/movies/2019/03/08/mary-poppins-returns-hear-missing-song-anthropomorphic-zoo/3097036002/
The sequence will also be featured in the extras on the Mary Poppins Returns Blu-Ray and DVD.