Blondeau walks the runway at the Dolce & Gabbana show during the Milan Fashion Week's fall/winter 2017-18 presentation in February. [Photo provided to China Daily]

Loubry was sanguine in the wake of that 2011 photo shoot in Vogue Paris that saw her little girl, and two fellow models of a similar age, sprawled across leopard pelts, wearing glittering mini dresses and dripping in jewels－red lipstick and manicures included.

A few months later, Loubry closed the Facebook page that had been set up for her daughter, apparently in reaction to the unwanted attention. She explained that "something's going wrong at the moment with Thylane", adding that she wanted to "protect" her daughter, who "doesn't know about the buzz".

It doesn't seem to have done her any long-term damage, however. Indeed, it won't have escaped the notice of eagle-eyed fashion followers that, earlier this summer, Blondeau became the face of Lolita Lempicka perfume. An ironic choice, perhaps, for a young model once embroiled in a row about the sexualization of children.

So why was Blondeau deemed so beautiful, so young?

Cosmetic doctor Michael Prager says that "it all boils down to proportions. I think what is most striking about the images of Blondeau when she was young is that she doesn't look like a 'normal' 6-year-old. She adheres much more to adult beauty proportions, with her strong chin and downturned mouth. It is confusing to the adult brain when you see these features on a young child."

"She was no Barbie, her face had interesting quirks that add intrigue. Her large blue eyes were quite widely spaced and she had a natural 'sulky' pout," agrees Dr Tatiana Lapa, who specializes in facial aesthetics. "At the age of 16, Thylane's face is very close to the 'ideal' Golden Ratio, a mathematical calculation of beauty. And she has a feminine heart-shaped face that will continue to mature, as the facial structure doesn't fully stabilize until you are in your 20s. Thylane still has some time to grow."

So "the most beautiful girl in the world" could yet become the most beautiful woman in the world. Prepare to see plenty more of her.

DAILY TELEGRAPH