“You might say the elderly have made way for the photo takers’ convenience, to not get in their way,” Hui concedes.

The building has long been a draw for street photographers and architecture enthusiasts, but social media has helped turn it into a mass tourist attraction, fuelled by its appearance in a recent Transformers blockbuster film and the remake of the Japanese manga classic Ghost in the Shell.

A sign warning against shooting photos and disturbing residents has done little to deter the chic travellers, who usually form an orderly line to wait for a coveted spot in the middle of symmetrical blocks.

A high-end cafe opened in November to cater to this new market. Its sleek interiors and bright lighting are a stark contrast to the more humble-looking neighbourhood shops and the public-housing towers above.

Other Hong Kong Instagram hot spots have proven even more chaotic. A mural by local graffiti artist Alex Croft featuring rows of tenement houses draws a constant stream of tourists to the steeply sloping Graham Street in the downtown Central district.

Taxis and cars honk restlessly as the tourists – mainly from mainland China, South Korea and Taiwan, but also Western nations – spill into the road to get their ideal frame, seemingly oblivious to the safety issues.

Park Tae and Hwang Seung-min from South Korea had only seen the wall free of interlopers in carefully composed photos on their Instagram feeds, so were surprised the street was so busy in real life.

“I was taken aback as I did not expect the crowds,” Park says. “But it’s good for taking photos.”

For some shops, this heavy foot traffic brings new business: there are queues outside a famous egg tart store and a dumpling house nearby, as snappers stop to refuel.

But Toby Cooper, who runs popular pub The Globe which sits directly opposite the mural, says the sheer number of people loitering on the road is a safety issue.

“We have seen a few people hit by cars and vans on Graham [Street] but they tend to be the Instagramers who are transfixed on taking photos,” he explains.

“Their saving grace is the sharp corner – vehicles entering Graham Street are going slowly. As far as I’m aware, none of my customers have been hit by cars, yet.”

Hong Kong’s unique urban aesthetics – especially its public housing estates – have proved enormously popular with social media obsessives.

Critics say the crowds help romanticise poverty, sharing images that provide only a shallow view of what it is like to live in one of the world’s least affordable property markets.

In Kowloon, tourists and some Hongkongers have taken over the basketball courts surrounded by a now iconic rainbow-coloured housing estate in the Choi Hung district, which means rainbow in Cantonese. It is where Korean boy band Seventeen shot a music video and it is now being promoted by the government’s tourism bureau.

Local resident Chow Keung, a 72-year-old kung fu master, is fairly sanguine about the visitors as he watches them from a bench.

“Many people have asked me how to get here and I give them directions, I don’t mind … but I’ve had to ask some tourists not to leave their trash behind,” he says, sighing.

A grandfather recalls a bygone era when children rode scooters and freely played basketball on the courts.

Today’s teens have to navigate the groups of photographers as they play. One 14-year-old resident says he now fears racking up a bill when he shoots hoops. “I once accidentally hit someone’s phone,” he explains.