It's a vigorous five second-long handshake between two international leaders that has gone viral, with some even fearing New Zealand's prime minister may have suffered a workplace injury.
As UK Prime Minister Boris Johnson greeted the visiting prime minister outside his Downing St residence for an official photocall, the symbolic greeting left observers on either side of the globe wondering what that handshake was all about and praising Ardern's diplomacy.
Lasting for at least five seconds, the firm, energetic shake is coupled with a pulling action, with the Johnson appearing to draw Ardern's arm towards him.
All the while the pair smile and position themselves for photographers, with Johnson ignoring shouted pointed questions about drowning in sleaze and whether he would take action over a politician facing groping allegations.
The unusual exchange has not been missed by people either side of the equator, with a clip going viral on social media and sparking a host of hilarious quips.
"Jacinda Ardern (NZ PM) nearly loses her right arm on the doorstep of No.10," posted Haggis_UK adding a facepalm emoji to highlight the oddity.
"Her whole body got shaken by Boris. I was expecting her to become airborne at any moment," wrote one UK Twitter user.
"It looked like he was trying to tear her arm off," wrote another from New Zealand.
"It's almost like he's trying to pull her somewhere, weird," wrote UK poster David Hazie.
"Someone call an ambulance, there's a woman at No. 10 that needs her right arm re-attaching!" posted London twitter user Janet.
Another commented on how fortunate it was for Ardern that we had ACC to cover any harm done during the encounter.
"Just as well we have ACC, real work injury risk right there," posted Allan Moyle.
Ardern went on to sign a deal with Britain's PM to let more Kiwis travel and work in the United Kingdom.
She has since wound up her European tour after meeting Prince William and is heading back to the southern hemisphere.