Todd Phillips’ Joker largely exists as its own thing and because of that, it mostly avoids any sort of allusions to the greater Batman mythos, with the notable exception being Bruce Wayne and the murder of his parents. It’s really a story about Arthur Fleck and Todd Phillips has explicitly said that he doesn’t do Easter eggs. However, on the special features on the Joker Blu-ray, the director admits to one intentional Batman Easter egg in the film.
In Joker, when Joaquin Phoenix’s Arthur Fleck goes to Wayne Manor he encounters a young Bruce Wayne. Bruce slides down a pole in his playhouse/jungle gym to go meet Arthur at the gates. It turns out that this was an Easter egg, as Todd Phillips explained:
I get asked a lot if that’s an Easter egg, and I just don’t like that term Easter egg, but little Bruce there when he slides down the pole, was that an Easter egg to the Batman television series and yes in fact it was. It was something we spoke about and thought ‘oh yeah, why not do it.’ Without being too cute we don’t like to do a ton of that stuff, but it felt appropriate.
So although Todd Phillips doesn’t like Easter eggs and doesn’t even like the term Easter egg, he admits that young Dante Pereira-Olsen’s Bruce Wayne sliding down the pole of his jungle gym falls under that designation. And although the director previously said that any Easter eggs were the result of the art department on Joker sneaking things in, this one was entirely intentional.
As Todd Phillips revealed on the home video release of Joker, Bruce sliding down the pole of his playhouse is an Easter egg reference for the Batman television series. In the 1966 television series Batman, Adam West and Burt Ward’s Batman and Robin would slide down their designated Batpoles from Wayne Manor to reach the Batcave. Bruce Wayne would always say “To the Batpoles!”
Todd Phillips and his team discussed including this Easter egg in Joker and ultimately decided to do it despite the director’s general aversion to such things. He figured ‘why not’ and we got this Easter egg for the great 60s Batman in Joker.
It seems that Todd Phillips was okay with doing this Easter egg just as long as it wasn’t too cute and as long as the film didn’t do a bunch of other Easter eggs in addition to it. Easter egg inclusion was a case-by-case basis it seems and in this instance, it felt appropriate. You can understand why Todd Phillips might be generally against Easter eggs for Joker though.
Joker is a somber character study and too many knowing Easter eggs and winking nods to stuff outside the film might take you out of it and shatter the atmosphere the film creates. So it’s rather funny that a ‘66 Batman reference made its way in considering how that light and fun depiction of these characters is the tonal opposite of Joker. But it’s so brief and subtle that I think you have to be really looking for that kind of thing and familiar with Batman to pick up on it.
A sequel has yet to be confirmed but I imagine that a Joker 2 would include more references to the Batman mythology. Todd Phillips has even said that he'd like to see a Batman movie set in the Joker world. In the meantime, after racking up tons of green at the box office, Joker is looking for gold this awards season. The film already nabbed two Golden Globes last night for Best Actor and Best Original Score.