A digital signage display on a Swedish subway platform reacts to passing trains, showing an ad with a model whose hair blows around her face when trains zip by, according to Mashable and The Huffington Post.
The digital out-of-home project is an ad for a line of pharmacy chain hair care products with the tagline "Make your hair come alive," according to Mashable. The subway platform ads in Stockholm were outfitted with ultrasonic sensors that detected oncoming trains, the site said. The ad featured a model with a lush mane, and when the train came, her hair flapped in the wind and she struggled to keep it in place.
"We needed to build a device that could be calibrated to sense the arrival of the train and not react to passing passengers," the production company Stopp Family, which designed the ad, wrote on its website, according to HuffPo. "Using an ultra sonic sensor, connected to a Raspberry Pi and a local network socket, we connected our device to the screens computer where the film could be activated by the passing trains."
Watch the ad in motion below: