"Please don't touch the artwork".
Now and then, we are reminded as to why these signs are still needed in galleries around the world.
She had tapped it with her finger, witnesses at the event said.
The statue - one of Koons' iconic Dog Balloons - smashed into tiny shards, and had to be swept into dustpans by gallery staff.
The accident happened during the exclusive VIP-only opening night of Art Wynwood, a contemporary art fair held annually in Miami, Florida.
Local artist Stephen Gamson told the Miami Herald he was admiring the sculpture, when an "older woman" tapped it, knocking it off its pedestal.
At first he wondered if it was part of a performance piece (Banksy, anyone?) but quickly realised it had been an accident.
Luckily for the woman, the piece is covered by insurance, Bénédicte Caluch, an art advisor with Bel-Air Fine Art galleries which represents the sculpture, said.
"It was an event!" Ms Caluch told the Miami Herald. "Everybody came to see what happened."
She added that the woman who caused the damage, who has remained unnamed, was an art collector.
"Life just stopped for 15 minutes with everyone around," Cédric Boero, who also works for Bel-Air Fine Art galleries, told the New York Times.
He added that a colleague spoke to the woman, who said she was "very very sorry" and "just wanted to disappear".
The sculpture was part of a limited edition which has now shrunk from 799 to 798.
"That's a good thing for the collectors," Mr Boero told the Times, laughing.
Despite being shattered into thousands of pieces, there is still interest in buying the destroyed sculpture.
Mr Gamson offered to buy it there and then because, as he said on his Instagram account, "it has a really cool story".
Jeff Koons, 68, has not made any comment on the incident.
His range of Balloon Dog sculptures are among the most iconic works of contemporary art, and have sold for tens of millions of dollars.
Some are enormous - as high as 10ft (3m) - but this ill fated one was just a puppy, at 16 inches (40cm) tall.
They have graced galleries around the world, and were further iconised by Jay-Z in 2017 when the rapper worked directly with Koons to create a 40-foot inflatable Balloon Dog for a stage prop.
In 2019 Koons made history when his Rabbit sculpture sold at auction for $91.1m (£71m) - the highest sale price ever for a living artist.