A Blockheaded Social Science Experiment. On Purpose.

They came from Westchester, Brooklyn, Long Island and the Bronx — actors young and old, seasoned and fresh out of the gate, summoned by casting agents for a rather curious gig: To stand around Astor Place in Manhattan early Thursday with mirrored cubes over their heads.

There were 20 mirrorheads in all, and they were being filmed for a short piece for the Tribeca Film Festival, which begins April 19. Festival organizers had adopted “seeing yourself in others” as a theme this year, as a partial curative to the nation’s bilious state of affairs, and their ad agency came up with the idea of conveying this theme of empathy via reflective blockheads, with the end product to run before screenings and online.

Staged scenes were planned for later in the shoot — portraits of a mirrorhead doorman, a mirrorhead homeless man, a mirrorhead Muslim walking alongside a Hasidic Jew. But Thursday’s plan was to set the mirrorheads loose and see how random onlookers reacted.

With the exception of a few people who had to be fitted in advance, none of the actors knew about the cube plan when they gathered at 6 a.m. in the East Village in the biting morning cold. All they knew was that they’d been hired as extras, to be paid in the very low three figures.

Then the plan was announced, and the cubes came out. Each had five mirrored sides, with elasticized black fabric on the bottom that hugged wearers’ necks. Built-in bicycle helmets held the cubes in place, and the front panels were two-way mirrors, so the actors could see where the heck they were going.

Soon the cubes were donned, and the performers were off, walking gingerly along sidewalks and making their way to Astor Place’s reinstalled sculpture of a huge cube.

Among the performers: Henry Williams, 71, a retired salesman and computer science teacher; Brigitte Williamson, 21, who has trained in experimental theater; and Hector Luis, who is in his 50s, lives in Suffolk County and still reminisces about the home his family almost bought back when they lived in Williamsburg, Brooklyn.

Asked what he thought of this gig, Mr. Luis chuckled. “I see the light bills getting paid,” he said, his voice slightly muffled by his cube. “It’s like being inside a building in here.”

Mr. Luis had found himself a place in the sun and was trying to shake off the morning chill. Interaction with passers-by, he said, had been minimal, and by 10 a.m., only two people had talked to him. “You’re the second,” he said.

More often than not, onlookers who stopped did what onlookers do these days: They captured the tableau with their phones.

“Most people are disconnected,” Mr. Luis sighed, fogging up his two-way mirror (a recurring problem, along with stuffiness, for the mirrorheads). “They experience life through their cellphones.”

Ms. Williamson, who was sitting in her mirrorhead at the base of the Astor Place cube, said the exercise reminded her of an episode from the dystopian television show “Black Mirror,” one in which a woman’s cries for help are ignored as people record her on their devices.

A gaggle of middle-school students charged by. “You’re supposed to see yourself in it!” one boy hollered. “No, I don’t get it!” another hollered back.

Others drank the scene in with delight.

Sara Alexander, 55, an accountant, said it seemed to her like an art project designed to get people to interact with one another.

“I love that it’s a reflection; we’re all a reflection of each other,” she said, smiling widely. “It’s fascinating, and part of the reason I live in this part of town.”

Linell Ajello, 47, who teaches writing at New York University, said the mirrorhead gathering underscored how people didn’t see each other as they passed in the streets.

A few onlookers asked the cube wearers what they were doing, if it was an art installation, whether they were being paid. One man positioned himself inside a group of cube wearers, took out his phone and spun about, as if recording panorama shots. Then he sauntered away, but not before sticking out his tongue at a woman who had been shooting pictures of him.

The intended message aside, it was unclear whether people were seeing themselves in others, or just looking at the heads and seeing themselves. “Most people don’t know I can see out; they’re taking pictures or videos as if I’m not here,” Linda Delores, 37, an actress from Manhattan, said inside her cube. “It’s the first time I felt that way — that I was somewhere and not there.”

At 10:30 a.m., Andrew Bennett, 62, who had traveled from Westchester for the job, got permission for a smoke break. Some of the cubes began checking their phones and, after everyone got approval for a pause, they all began carefully pulling off the mirrored heads. Mr. Williams, the Bronx retiree, closely examined his cube’s interior; something in there had been digging into his head. Ryan Campbell, a 29-year-old actor from Hell’s Kitchen, looked into his cube and began fixing his hair and goatee.

Between drags of his cigarette, his cube partly lifted to free up his mouth, Mr. Bennett said that the whole experience was “bizarre at least, but it’s fine.”

“Not many people could say they stood around all day with a cube on their head,” he said.