For those that don’t know Jim and Aerial Contrivance Workshop developed and storyboarded the animated sequence for Mary Poppins Returns from May of 2016 to April of 2017. Jim then went on to oversee the animation production of the sequence to its conclusion in July of 2018. The animation, a tour de force of classic 2D drawn animation combined with the latest tools and technology of today was produced at Duncan Studios in Pasadena and Framestore in Montreal. It has garnered some wonderful reviews and notice and all involved are very proud of what was accomplished.
You can read a bit about it here in this wonderful NYT article on the animation :