In the opening scene of the film Roma, soapy water splashes across the screen. It’s the product of the protagonist, Cleo, scrubbing the driveway and cleaning up dog mess, which her employers, a middle-class Mexican family, chide her for not removing promptly.

The scene, however simple and aesthetically pleasing, sends a subtle message that many Mexican moviegoers immediately understand about domestic workers like Cleo and the confusing status in the households they serve.

“It’s clearly trying to say: this maid doesn’t only work for the family but she even works for the dog. She cleans up the dog’s shit,” said Gary Alazraki, a Mexican filmmaker and producer.

“That’s her status in the family and yet she is so loved. They give her a home but they won’t give her electricity for her rooftop room. They [Cleo and her colleague] are part of the family but then they are an underclass,” he continued. “The movie’s success lies in its heart, which is that many of us grew up in a home where a nanny became part of the family in a very perverse way.”

Since it was released late last year, Roma has won acclaim and awards – most recently a Golden Globe – and could next month capture Mexico’s first foreign-language film Oscar. It has catapulted its star, Yalitza Aparicio, into the global spotlight and onto the cover of Vogue’s Mexican edition – a first for an indigenous woman. But it has also prompted serious soul-searching about the plight of poorly paid and often-unprotected domestic workers in Mexico, where, nearly five decades after the period depicted in the film, inequality remains rife, racism stubbornly persists and social mobility seems to have stagnated.

“What [the director] Alfonso Cuarón wanted to say in his film is: ‘look at the country in which I grew up in, how different it was and how much it hasn’t changed. And that’s not a good thing,’” Alazraki said.

Named after the then-bourgeois Mexico City neighbourhood in which Cuarón was raised and the film is set, Roma has made an impression on the middle and upper classes even as it addresses uncomfortable issues such as race and class in a country where 43% of the population is poor.

“I think it’s the kind of film that appeals to a certain kind of middle- and upper-income audience of a liberal persuasion, who see the film as putting into cinematic language a lot of their own concerns about class and race division in Mexico,” said Andrew Paxman, professor at Mexico City’s Centre for Research and Teaching in Economics.

“It’s not a lecturing film,” he said. “In Mexican cinema … the poor are noble and the rich are bastards. Roma is very fresh in this regard. It’s not vilifying the employers. These are all well-rounded human beings, and that makes this film so innovative.”

Roma’s release – first in cinemas and then on Netflix – coincided with political change in Mexico. President Andrés Manuel López Obrador swept into office in December, promising to combat inequality and put the priorities of poor and indigenous Mexicans first.

He stokes nostalgia for past decades in the country, when the economy grew rapidly and the middle class expanded – the so-called Mexican miracle, which ran for nearly three decades after the second world war, and the tail end of which was captured in Roma, set in the early 1970s. When the culture ministry organised a special screening of Roma, it did so at Los Pinos, the presidential palace that López Obrador refuses to live in and opened to the public as a museum.

But some facets of Mexican life remain stubbornly resistant to change. Examples of women like Cleo are still common, said Marcelina Bautista, founder of a union for domestic workers. Providing food and lodging is often offered as an excuse for not paying proper wages, Bautista said.

“It’s a way to cheat and avoid the responsibilities that a person assumes when hiring someone, [and] when we demand our wages they come out and say we’re ingrates for being so demanding and unthankful for having a roof over our heads and food,” she said.

Ingrained prejudice has also been reflected in media coverage of the film, with headlines referring to Cleo with disparaging words like “servant” and muchacha (girl, as maids are commonly called).

The release of Roma was “raising consciousness”, Bautista added. “Many domestic workers really identify with the film.”

And change could also come from the supreme court, which last month ruled in favour of domestic workers, who, as informal employees, petitioned for their labour rights and to receive social benefits such as healthcare and pensions.

I think it is one of Mexico's most serious cinematic attempts at dealing with racism
Rodolfo Soriano-Núñez, historian

For some, Roma has caused discomforting memories of their own families’ treatment of domestic staff. “I have not been able to watch it because of all the memories of the 1970s,” said Rodolfo Soriano-Núñez, a Mexico City sociologist. Soriano-Núñez recalls his own grandmother verbally “bullying” the hired help or denigrating her in front of family.

“I think it is one of Mexico’s most serious cinematic attempts at dealing with racism since Luis Buñuel’s Los Olvidados,” which was released in 1950, he said.

The film’s middle-class appeal has been undeniable, though. Observers say much of it stems from its portrayal of a time when the middle class could live comfortably and security was provided, even if it was through the might of a politically repressive regime.

The time, however sinister, still appealed to some in a population weary of crimes such as kidnapping and extortion and seeing drug cartels and lethal fuel-theft gangs operating with impunity, said Harim Gutiérrez, historian at the Metropolitan Autonomous University.

“Roma depicts the swansong of the middle class produced by the Mexican miracle,” under the old political regime, Gutiérrez said.

“It was a time when a physician who worked for the government could have the purchasing power to maintain a household the same size as this family had,” he added. “They could have a higher standard of living … with jobs that today barely allow for survival.”