A 25-year-old artist in Beijing who calls himself ROBBBB has found a unique canvas for his work, one he hopes helps capture the fast-paced changes in China's capital: the walls of abandoned and half-demolished buildings.

On crumbling edifices down alleys or by construction sites, he has glued enlarged images of photographs of people from around the city, sometimes striking unlikely poses.

One well-worn wall depicts a man in a suit kneeling and holding out a glowing flower among piles of debris. Another series is made up of huge images of smiling faces stuck to broken walls around the city, which like many in China is dotted with demolition and construction sites. Other images show legs that appear to stick up out of the ground.