In a behind-the-scenes video, the 17-year-old pop star breaks down the production trickery required to make it appear as though she was walking up walls and along the ceiling. The trick is fairly straightforward, and an old one; as Eilish notes in the video, it was inspired by a similar sequence in the 1951 Fred Astaire film Royal Wedding. The SNL crew built a special rotating set with a camera locked in place on the set to rotate along with it, creating the appearance of Eilish flouting the laws of physics.
It’s an easier idea to grasp once you see it, as Eilish understood: The video shows a homemade recording of Eilish demonstrating the concept, and the timing of the performance, with a tissue box and her finger. The video also offers glimpses of the set being constructed, and of the various rehearsals required to perfect the timing (“We have had more rehearsal time than any other thing we’ve done,” Eilish says). And if you weren’t already impressed, Eilish also reveals that she performed with two sprained ankles, with one foot in a boot and one in a brace.
“The fact that they even trusted us to pull this off is really big, because I don’t even know if I would’ve,” Eilish says with a laugh. “I know they’ve never done anything like it, so I’m really, really grateful that they were open to it and understood and believed in us, and believed in me,” she adds.
You can watch the full video above.