3. Jack is meant to mirror Bert … but this newcomer also has a connection to the old chimney sweep.
Lin-Manuel Miranda’s character, lamplighter Jack, shares a few traits with Mary Poppins’ old companion: He works on the streets of London, he likes to say “as I live and breathe” when he encounters Mary Poppins and he’s played by an American actor with a goofy fake Cockney accent.
But Jack’s backstory also lines up with the original film. We learn he grew up working for Bert (Dick Van Dyke in the 1964 version), who’s currently traveling the world (as the only returning cast member, it would be strange to see Bert about 30 years older than he should be).
Jack also reveals that as a kid, he would pass by the Banks house and wave to Jane through her bedroom window.