It’s a tall feat for an advertiser to stand out in Times Square, which is swathed in giant plasma-screen billboards. But today, a taste of what billboards might become is being unveiled–and the billboard reaches out and grabs the crowd, thanks to technology borrowed from high-tech spy cameras.

Designed by interactive agency Space150 for Forever 21, the billboard features a model walking in front of an image of the crowd below. And then it gets interesting: The model occasionally leans over, and appears to pluck someone out of the crowd. Sometimes, they stink, so she tosses them. Sometimes she kisses them, and they turn into a frog. And sometimes, she drops them in her bag and happily trots off. At one point, the model takes a Polaroid of the crowd, shakes it out, and brandishes it in front of her–showing off a zoomed-in image of the people below.

The billboard just went live at 10 a.m. this morning, but during tests, hundreds of tourists have stopped, dead still and gawked. “Since it sits above a pedestrianized part of Times Square, we knew there would be big crowds in front of this billboard all day,” says James Squires, Space150’s director of technology. “But people only look at billboards for six seconds on average. We wanted to extend that.”

The billboard relies on technology that’s usually used in government or security surveillance, and Space150 had to consult surveillance experts to pull it off. Above the 61-foot-high face a high definition Prosilica camera captures the crowd. But then, software picks apart the individuals in the crowd, and selects some for a digital composite built in real-time, which is then used in the interactions with the virtual model on screen.