How Billie Eilish performed upside down on SNL

With a little bit of TV trickery, Billie Eilish was able to perform her hit "bad guy" upside down on Saturday Night Live.

This behind-the-scenes video shows how it was done:

Duh.

Ms. Eilish isn't the only talent to perform upside down live on SNL. You may remember that Penn & Teller did it first in 1986.