Even if you missed seeing Kara Walker’s 75-foot-long nude mammy-sphinx in person at the Domino Sugar Factory this summer, chances are you saw it on Instagram. Maybe with someone faux-tweaking a nipple or sticking a tongue out toward its colossal vulva. Very quickly, the work, A Subtlety, became the notorious focus of many, many thousands of sometimes-tasteless selfies — a spectacle with unclear racial politics that turned many visitors off, even as thousands of others flocked to the show to take part.

As it turns out, Walker had been “spying” on the crowd, secretly recording visitors for the new 28-minute video "An Audience," debuting Friday at Sikkema Jenkins & Co., through January 17.