A small photograph for a school application form no longer means five minutes in a photo booth but an hour-long session at a professional studio.
The resulting photoshopped picture is designed to show principals that the applicant, often a toddler, is just the type of child they want in their school.
But how do the photographers, or the parents, know what type of children principals like? This is where playgroups aimed at toddlers under two, preschool and primary-school interview classes come in, with their connections to those in charge of various schools.
"This is a business chain, with one section linked to another," says Jackson Yim Chi-lung, owner of one photo studio popular with parents.
Yim has photographed playgroup application pictures where the children are not even a year old. Some cannot yet walk and have still to cut a first tooth. Popular playgroups can be picky, and some require interviews after shortlisting candidates.
Yim's studio, Pak Hop Photo, charges parents HK$980 for a CD of pictures of their children, retouched to remove any imperfections. The backgrounds, added after the shoot, add colours aimed at portraying different personality traits - outgoing, reserved, mature or innocent - according to the principals' tastes.
If parents want a portfolio album, they need to pay HK$3,800.
Yim takes an hour on average to bring out the desired characteristics. The secret is to communicate with the children patiently, he says.
For portfolios, parents also require that he sets aside several pages for photos of family trips. "There are things you can use to tell the principals which class you belong to," Yim says. "Children at that age are too young to have any experiences to compare, so you start to compare their parents."
Some parents ask him to take photos of their children alongside awards they have brought in with them. He tried to persuade one child's parents against one shot that he considered "too loud", but they insisted on it. The five-year-old was consequently pictured standing proudly behind 25 trophies and medals.
Some parents whose children do not have such a trophy cabinet have resorted to having their children pictured next to the "Love Teeth with Your Kids" award - a certificate given out as part of the government's oral-health programme now known as Brighter Smiles for the New Generation.
Started in the 1980s, Pak Hop Photo is one of the best known studios in Sha Tin, with prominent politicians and even Nobel Prize-winning physicist Yang Chen-ning among its clients. But its "interview photos" are a relatively new specialty.
Yim, who took over the business from his father in 1997, found an increasing number of parents coming to have pictures taken of their children for school application forms and it was not long before he realised this was a new market.
He started to advertise the service in 2008 and business has been growing ever since.
Recently some principals have started asking the parents to submit a maximum of five A4 sheets, including CVs and photos. In some cases, one elite primary school principal says, they were having to deal with 30 to 40 pages of photos and text.
"But parents have a solution to this," Yim says.
"They ask me to shrink the photocopies of their children's certificates and cram a dozen of them on one A4 sheet."