Garment worker Khieu Mok put in a 24-hour shift so she could take time off to vote in last month’s elections.

On July 28, at her hometown pagoda in Svay Rieng province, she held her ink-stained finger to the camera lens of film director Kalyanee Mam, who has followed her story for the past five years.

“The current wages [$80 a month] aren’t enough to live off. For now I only ask for $150,” she said.

Then, minutes after voting, she was on the back of a motorbike bound for Phnom Penh and the factory.

The three-minute footage captured last week by Mam, will be released as a short follow-up to her acclaimed documentary A River Changes Course. The feature-length film, which won this year’s World Cinema Grand Jury Prize at Sundance Film Festival, records Mok’s struggle as she leaves the rice fields for the factories of Phnom Penh.

Director Mam returned to Cambodia from the US in the lead-up to the election to screen the film to universities and villages around the country, aiming to cultivate a dialogue among voters on the country’s future. On Friday, she screened the film in Mok’s own living quarters.

Shot over a four-year period, the documentary follows the stories of Mok and two other Cambodians: a young, poor Cham fisherman from Kampong Chhnang and a mother living in remote Ratanakkiri.

All are trapped in poverty as the country rapidly develops, the forests are logged, the rivers depleted of fish and the Mekong dammed.

Last week, screenings were held in Battambang, Phnom Penh’s Meta House as well as Mok’s shared dormitory on the outskirts of Phnom Penh.

Mam said she had no expectations about how the audiences would respond.

“I always forget about the [impact of the] film,” said Mam, explaining that her first thought was of the personal effect it had on Khieu and the others.

On Friday, as the film was played at her cramped, communal dormitory home outskirts of Phnom Penh, 30-year-old Mok stood confidently in front of hundreds of her fellow workers.

The women watched, leaning over balconies and lined up against damp walls and on mats on the floor. The reception was as boisterous as it was poignant.

They laughed and poked fun at village scenes of Mok working the rice fields, of her mother struggling to pay off loans, and Mok coining her mother’s aching shoulders.

Silence descended when Mok was shown climbing into a mini-van, heading for the first time to life in the factories, her mother wiping away tears. There was quiet when the leaky factory quarters appeared and Mok said she felt her life was “divided in half”.

In the final scene, where Cham teenager Math talks about hopes being dashed and of the future, a woman called out. “This is us. Our story. How can we ever be happy in this difficult life?”

Afterwards, inside Mok’s small room – a confined cooking, eating and sleeping space she shares with seven others – she expressed her hope that A River Changes Course would shape people’s perspectives in Cambodia and abroad.

“In Cambodia, the rich have it easy and the poor like me really have it hard.

“Everyone has a different perspective on life. But I hope some can be changed so that all Cambodians can work together to improve the country.”