As the Paris gymnastics arena roared on American Simone Biles for her third gold medal of the 2024 Olympics, one of those applauding was none other than An Chang-ok, a rival from North Korea.

Saturday’s women’s vault final saw the North share a stage with its foes South Korea and the US.

An, 21, grinned and waved for TV cameras and hugged at least one fellow finalist - rare interactions with foreigners by a young woman required to perform diplomatic gymnastics while being carefully chaperoned on her trip away from home.

Pyongyang’s decision to send athletes to these Games – two of whom even posed for a selfie with rivals from the South - has raised hopes that the secretive state could be partially reopening after a particularly deep period of isolation.

After all, this comes after a heated period that has seen the North sending waste-filled balloons at the South.

The North’s participation in these Games signalled a “remarkable” return to the international fold, suggested Jean H Lee, a former Associated Press journalist who opened the US news agency’s first bureau in the North Korean capital, Pyongyang.

It did not send any athletes to the Tokyo Olympics, held in 2021, after the country shut itself off from the world even more sternly than usual due to the Covid-19 pandemic.

But in Paris, it was “making the effort to rejoin the international community”, Lee said, “regardless of what’s happening with their nuclear programme, which is always the elephant in the room”.

The North’s nuclear ambitions are an enduring cause of tension with the South and the US. But there was no sign of animosity between the three nations’ gymnasts on Saturday.

This new generation of North Korean athletes have claimed two silvers in Paris, and occasionally surprised sport commentators who did not know what to expect from them.

Winning medals was not the country's only aim, according to Prof Ramon Pacheco Pardo of King’s College London, who has written extensively on the two Koreas.

The age-old North Korean art of “sports diplomacy” involved limited participation in a global forum to prove the country was normal, Prof Pacheco Pardo said. Athletes were some of the “few actors that North Korea has who won’t be viewed suspiciously” by the world, he explained.

The contrasting support for An and Biles could not have been starker. In an earlier competition during the Games in Paris, Biles was memorably cheered on by a host of celebrity supporters in the stands, including Lady Gaga, Ariana Grande, Tom Cruise and Snoop Dogg. Thousands of punters yelled her name on Saturday, too.

An, meanwhile, received only polite appreciation from the neutrals. She had no compatriots in the room, since ordinary North Koreans are prevented from leaving their country.

It is unlikely that anyone was watching at home, either, as the Games are not being televised live in North Korea, according to Radio Free Asia (RFA). And BBC Monitoring has only been able to find a handful of text reports in the tightly-controlled state media.

Nonetheless, “the chattering class of Pyongyang certainly will, from one source or another” know the Olympic results as they come in, said John Everard, the UK’s ambassador to North Korea from 2006 to 2008.

An is among 16 North Korean who athletes have come to an opulent host city that could hardly be more different to the austere Pyongyang airport in which they were filmed setting off last month.

Top North Korean athletes were likely to have some awareness of the outside world, said Everard, but there was still likely to be a “shock factor”.

One of the viral moments of the Games so far was a rare encounter that seemed to break the boundaries: when a bronze-winning South Korean table-tennis player took a selfie that showed his mixed-doubles partner posing alongside the silver-winning North Korean duo.

Would the leadership in Pyongyang have anticipated – or relished – this brief symbol of unity between two nations who are still technically at war?

Agreeing to the selfie was “a message” from the North, said Prof Pachedo Pardo, who speculated that the move would have had Pyongyang’s consent. “North Korea is indicating that it doesn’t have a problem with South Korean people - that the issue it has is with the South Korean government.”

At any rate, the moment was not totally unexpected, after something similar in 2016. And two years later, North and South fielded a joint women’s ice hockey team at the Winter Games in the South.

The selfie represents one of the North’s few visible interactions with the outside world during the Games, including a perfunctory press conference by the two table-tennis stars.

Away from the stadiums, unverified footage has appeared to show An holding a collection of pin-badges, which are reported to be an item popularly traded by international gymnasts.

After so much exposure to the Western world, the athletes will probably undergo a gruelling “debrief” after returning home to ensure they stay on-message, said Lee, who is also the co-host of the BBC World Service’s Lazarus Heist podcast.

Contrary to the myth, any athlete deemed to have “failed” would probably not be punished, the analysts agreed. But they could face gruelling “self-criticism” sessions.

“The big hit for not winning a medal isn’t so much the punishment, it’s that you don’t gain all the benefits that you could have gained,” said Everard. Victorious athletes may be given higher status in society and even prizes such as a new home.

It remains to be seen whether this latest sporting diplomacy will translate into meaningful new talks between the two Koreas. The relative bonhomie in Paris was briefly imperilled at the outset by a furore when organisers mixed up the two nations’ names in the opening ceremony, for which they apologised.

Outside the Bercy Arena after Saturday’s gymnastics, one fan from the Seoul side was not convinced the politics would change much.

But she said the sight of sportspeople sharing a stage was at least a reminder that all Koreans were united by something “human”.