Darwin-born video artist Tiyan Melissa Kilie Baker says she was struck by the rapid and traumatic change unfolding in Beijing while spending six months there this year. Her response was a subtle and meditative series of three video portraits of locals re-creating their favourite memories of a life that is fast disappearing.

One is sitting in a park after running, another is waiting on the steps of a large building at night, and the third is staring over a bridge as time and traffic pass by.

All three appear fixed in time but are moving almost imperceptibly.

"We often read in the paper about all these crazy figures, but actually these are real people, and it's really hard to live there, it's so hard to be Chinese, it's so hard to live in Beijing and feel like a human - it's a really rough environment," Baker said on Friday after learning she had won the Macquarie digital art prize.

"So these portraits are an attempt to rediscover humanity and reaffirm identity and preserve it as well, which is why there are loops, and provide sanctuary in a space that's really tough."

The 25-year-old is the third annual winner of the $10,000 prize, which began as a way of exploring the nexus between portraiture and digital screen-based expression.

The prize is open to any Australian resident aged 18-30, and entries must be able to be displayed on a screen.

The three judges said this year's entries showed a much greater clarity and technical expertise.

"What we're looking at are artistic works that are different to a short film, they're different to certain types of contemporary art work, they're exploring ideas of selfhood and identity," said judge Chris Chapman, the gallery's senior curator.

"I think that we've found that over the past three years we've been increasingly receiving entries that explore that in a very clear way."

Fellow judge Gillian Raymond, who is the gallery's online manager, said she was struck by the beauty and technical brilliance of Baker's work. "It's a combination of the technical expertise and the thought that's put into the story or the construction of the project that really sells it as a winner," she said.

Judge Jeff Khan, who is artistic director of Performance Space Sydney, said he was impressed by the gravitas and simplicity of Baker's work, which was simultaneously tackling a complex subject.

"It has a sort of level of introspection and melancholy that you wouldn't necessarily expect from a digital portrait," he said. "I think it's the fact that it is this engagement with the idea of digital portraiture, but to create something that's about loss of history and identity in such a moving way."

Entries in the Macquarie award are on display at the National Portrait Gallery until November 23.