The movie about the origins of Batman's greatest nemesis, directed by Todd Phillips, was a total hit, having raked in more than USD1,072,722,593 (RM4,581,061,833.41) worldwide, making it the most profitable comic book movie ever made.

Joaquin Phoenix, who played the titular character, also walked home with the Best Actor award at the 2019 Oscars.

Even though the movie came out last year, fans are still discovering some cool hidden Easter Eggs in the movie - and the latest one is definitely going to blow your mind!

Clever trick?

According to the The Mirror UK, the Easter Egg in question appears very early on in the movie, when Arthur Fleck was sitting in front of a dressing table applying his iconic clown make-up.

It may seem just like an ordinary scene, but one fan pointed out on Reddit that if you pause the scene at the right moment, you'll notice a familiar face glaring back at you.

Here's the scene. Let us know if you spot anything:

Did you spot it? Well, you have to squint really hard and pay attention to the details.

Still no? OK, let us help you out a little more:

Can you see it now? If your answer is: 'Yep, there's a guy behind him', congratulations...you do not have the eyes of an eagle.

This is what the fan saw:

Yup, that's the face of Joker's ultimate archenemy, Batman, staring right back at you.

The dark outline created by the fittings of the mirror, as well as Fleck's sitting position and the placement of the prop above the mirror, plus the two hanging lights in the background appear to perfectly form Batman's unmistakable cowl.

As we pick up the pieces of our mind that's obviously been blown, another fan pointed out that the the Dark Knight's cowl looks clearer if you flip the image upside down.

"You got it upside down, flip the picture over and you can even see the lips. And it makes sense for it to be upside down since the Joker is the antithesis of Batman."

Holy smokes, Batman!

It actually does look like this guy:

Was it a coincidence?

Netizens who saw the pictures were divided; some claimed that if it was intentional, then it was a brilliant touch by the director and the producers, but they were some who claimed that it was just a coincidence.

One Reddit user wrote: "I just turned it upside down and screamed. It’s so perfect. HOW CAN THIS NOT BE INTENTIONAL."

Another added: "Man, if this was intentional and sort [of] like an Easter egg, then this was a damn good one."

"Bats sleep upside down," said another.

One Reddit user refused to believe that it was intentional, claiming: "I am highly skeptical that this is purposeful. Like what would the purpose of this be? And it's barely the shape."

"That's pretty neat, but this is 100% a coincidence," another user agreed.

We may never know if this was done intentionally, but if you ask director Todd Phillips, he would tell you that he'll never insert Easter Eggs into his movies.

"I don’t do Easter eggs. Any Easter eggs anybody finds is a mistake," he told US entertainment site Collider in an interview.

Even if fans do find some sort of Easter eggs, Phillips insisted that it would be the work of his "art department sneaking something in that would make me crazy if I knew about it."