The Tonight Show host Fallon, 39, had Holmes, 35, on the show to promote her new movie The Giver, but they got sidetracked with games and laughter.
One such diversion was a new Tonight Show game called Photo Booth.
"So there's this great app on the iPad called photo booth, where you can take weird photos of yourself," Fallon explained. "What we're gonna do is, we're gonna take turns making ourselves look as weird as possible, then see if the other person can match it."
After encouraging viewers to play along at home, Fallon and Holmes each picked up iPads and tried out their best funny faces.
Puffing out their cheeks and squinting their eyes, the stars utilized a variety of distorting effects on the camera, yielding some hilarious results.
Watch the charming video above!