Did you find the Easter egg made of tamales in Oscar front-runner 'Birdman'?

The director of Birdman hid a piece of Mexico City in New York's Times Square during the filming.

Even if you haven’t seen the Academy Award-nominated 'Birdman,' you’ve probably heard about this scene: Riggin Thomson (Michael Keaton) speedwalking through Times Square in nothing but socks and his skivvies.

That moment in a film nominated for nine Oscars Sunday night has received a lot of attention for how it was made. It was shot live in arguably the most touristy spot of New York City with just a few actors planted in the crowd.

Despite the location and the actor – both very USA ­– tucked away in the scene is a very singular homage to Director Alejandro González Iñárritu and sound designer Martín Hernández’s native Mexico.

If you’ve never set foot in Mexico City, you might have missed it.

Sidewalks here are alive with unique sounds – organ grinders, hodgepodge “bands” pounding drums, ringing bells, and playing the clarinet, and men and women pumping accordions. Recordings blare from trucks around the city offering to take old mattresses and refrigerators off your hands, and you can even hear the sporadic mariachi band.

And then, there’s the tamale man.

Possibly the most ubiquitous sound of the city, a recording of a single, monotone, guttural male voice plays from the tricycle of nearly every tamale seller here.

“Ricos, deliciosos, y calientitos tamales oaxaqueños,” (Rich, delicious, and hot Oaxacan tamales) the voice calls, luring hungry Chilangos, as Mexico City residents are called, out of their apartments and onto the street.

The tamale man made a cameo in 'Birdman’s' Times Square.

“We put it in all of his movies,” Mr. Hernández told The Associated Press, referring to Mr. Iñárritu’s work. “I won’t tell you (where), it’s like ‘Where’s Waldo.’”

Iñárritu isn’t the only Mexican director to include references to home in his Hollywood films, says Ignacio Sánchez Prado, associate professor of Latin American studies at Washington University in St. Louis.

Take Alfonso Cuarón, who last year became the first Mexican to win best director, for his film Gravity.

In Harry Potter and the Prisoner of Azkaban, directed by Mr. Cuarón, there are multiple references to Mexico, like sugar skulls – a common accoutrement for Day of the Dead festivities – in the candy store Honeydukes in Hogsmead. There are also several statues of eagles devouring snakes on the Hogwarts campus, an image prominent on the Mexican flag. And at one point Dumbledore can be heard humming “La Raspa,” also known as the Mexican hat dance.

They “play these cards sometimes to be able to wink back at the Mexican market, where they still have producing influence,” says Mr. Prado via email. They aren’t noticeable to average spectators, and “it’s a fun thing to do.”