“Most people who live in L.A., when they see a photograph of an abandoned sofa, to them it’s like, ‘Oh, my God. I know exactly’ — they can’t get the words out,” he said. “Because they understand it.”

Abandoned couches are not unique to Los Angeles. But their ubiquity has made them in a way synonymous with the city.

A sanitation spokeswoman, Heather Johnson, said she couldn’t immediately provide figures on sofa removals. But she said more than 30,000 tons of “bulky items” were collected in scheduled pickups in 2016.

Mr. Ward, 45, who is Irish-born and works as an assistant director in Hollywood for his day job, said when you start paying attention, you see the couches everywhere.

“I call it the Ikea-ization of our homes,” he said. “Furniture sort of becomes disposable.”

Los Angeles’s transitory population also likely plays a part. More than half of residents are renters, people perhaps less devoted to their neighborhoods than owners.