Every car can accelerate, brake and turn. But only the Tesla Model X can put on a three-minute dance performance.
The windows open, the speakers blast a holiday carol, the exterior lights flash in sequence, the front doors open and close, and the gull-wing doors rise, arch and flap to the music.
That roboshow is an Easter egg: an undocumented feature in a tech product, set in motion by a sequence of commands that nobody would hit accidentally.
Over the years, Easter eggs in tech products have largely disappeared (except in video games). Like any other software, Easter eggs, so named for the hunt to find them, cost time and money to design, build and debug. Why would a tech company develop features it can’t advertise or even reveal?
In the beginning, the answer was revenge.
In 1976, Warner Communications bought Atari, the video game maker. The game designer Warren Robinett, then 25, chafed under his new employer.
“There was a culture clash between the New York people and the California people,” Mr. Robinett said. “We wore T-shirts, and had long hair and beards, and came to work whenever we pleased.”
Worst of all, the new bosses had no intention of giving credit to the authors of their games. And so, as an act of civil disobedience, Mr. Robinett built what is generally credited as the first Easter egg into his game “Adventure” — a flashing, colored credits screen that read “Created by Warren Robinett.”
To avoid detection by Atari’s testers, he hid it in a secret “room” of the video game, accessed by a convoluted sequence of steps involving a maze, a bridge and a one-pixel “key” that he called The Dot.
His bid for recognition eventually paid off spectacularly — in Steven Spielberg’s 2018 movie “Ready Player One.” To save his world at the movie’s climax, Parzival, the hero, must play Atari “Adventure” and unlock its Easter egg. “You see, Warren Robinett was proud of Adventure,” Parzival explains as he plays. “That’s why he created the first digital Easter egg!”
These days, Easter eggs are anything but acts of defiance. They are meant to entertain, to lure potential hires, to pay tribute to executives — or to amuse the programmers themselves.
At Google, there is a long tradition of Easter eggs, which have the full support of the company.
“It helps establish software as an art form, following in the footsteps of painters and musicians and craftspeople sneaking little jokes and references into their work for literally centuries,” said Dan Sandler, who works on the Android smartphone software.
Mr. Sandler has built an eggy surprise into every version of Android since 2011. For the current version — Android P — he created a secret painting app.
“One of the themes in the P release was ‘digital well being,’ the idea that you should be able to choose a balance of screen time and non-screen time,” he said. “In my paint app, over time, the strokes you draw fade away to nothing, like a Zen drawing board.” (He notes that you can tap the hourglass to pause the timer, “if you must.”)
There’s no Save command, either. “This is another Zen thing: Don’t cling to your creations,” he said.
In the Google Maps division, the best-known Easter egg appeared on March 10, 2018. It was International Mario Day (Mar10, get it?), celebrating the goofy Italian plumber from Nintendo’s video games.
On that day, the usual blue dot on the map, representing your location as you drive, appeared as Mario in his little go-kart. The project was a collaboration with Nintendo, which supplied the 3-D Mario artwork and audio recordings of Mario’s cheery voice (“Woo hoo! Let’s a-go!”).
“To be honest, I wasn’t super excited about the idea,” said Munish Dabas, the Google Maps interface lead. “The last thing we wanted is something we’d get a lot of negative feedback or press about.”
But Mario Maps was a social-media hit. “The only negative feedback I saw was people asking, ‘Why can’t we have this as a permanent feature?’” he said.
Easter eggs have become so entrenched in Google’s culture that two Google Search engineers, Josh Ain and Colin Tincknell, have informally formalized the practice. They give talks for colleagues about creating Easter eggs; maintain an internal email group about Easter eggs (called “Poultry”); and have created software tools that make it “ridiculously easy” for their colleagues to add Easter eggs to Google search results.
(If you’ve seen “Avengers: Endgame,” don’t miss their finest work. Search for “Thanos” and then click the bejeweled gauntlet icon.)
“We focus on how much people are sharing this, how much people are delighted by it,” said Mr. Ain. “And we think it’s good for Google.”
At Amazon, the only known Easter eggs were planted by Amazon’s chief executive and founder, Jeff Bezos.
One is a permanent tribute to David Risher, the man Mr. Bezos charged with transforming the Amazon of 1997 — an online bookstore — into an everything store. That took Mr. Risher five and a half years. At that point, having built Amazon’s stores into a $4 billion enterprise, Mr. Risher decided to move on.
Just before Mr. Risher’s departure, at his final all-company meeting, Mr. Bezos called him up to the stage. The Amazon website appeared on the big screen. Beneath the copyright date on Amazon’s store-directory page, Mr. Bezos had hidden an invisible link. It opens a secret note: “Thank You, David Risher,” it begins. “Your contributions will live forever in the form of an ever-evolving Amazon.com.”
“And he does his laugh,” Mr. Risher said. “And I’m like, ‘Oh my god!’ And then we gave each other this huge hug.”
Sometimes, an Easter egg’s target is neither the public nor a cherished employee. It’s prospective hires.
That’s why Matt Mullenweg, co-creator of the WordPress web-creation software, has built so many Easter eggs into his company’s website, Automattic.com.
If, for example, you return to a certain job on the company’s hiring site more than five times, a message appears: “We couldn’t help but notice that you’ve visited this page a few times. Give a shot and apply already!”
Another Easter egg on that site is so hidden, fewer than a dozen people have ever found it, Mr. Mullenweg said. He has hired almost all of them. He prefers not to describe the Easter egg, so it can continue its work as a test for potential applicants.
He is also responsible for the Easter egg that’s hiding 5,274 words into the WordPress Terms of Service page, in a paragraph called “Disclaimer of Warranties.” It says: “If you’re actually reading this, here’s a treat.”
The link then opens a photograph of beef brisket and a tribute to Memphis Minnie’s, a San Francisco barbecue restaurant. Mr. Mullenweg noted that because he makes this Terms of Service document available to anyone, “this Easter egg has actually been copied into many other companies’ terms of service, without them reading or noticing it.”
As for Tesla’s dancing-car trick: It joins a long list of animated surprises that Tesla drivers can summon.
Those include Romance Mode (the screen in the car displays a crackling fireplace as a mood-setting pop song begins to play); Santa Mode (your car’s icon on the screen becomes a sleigh, snowflakes fall, and the turn signal produces the sound of jingle bells); and what Tesla engineers call Emissions Testing Mode (you, the driver, can trigger the sound of flatulence emerging from any of the car’s seats).
Eventually, Tesla’s engineers made them easier to find: Today, a single screen offers icons to tap for most of them.
But not all. Tesla has confirmed that its cars still contain Easter eggs that nobody has yet discovered.
The hunt continues.
Additional production by Alana Celii