As Maya and Kristen performed an impromptu medley, the camera flashed to the 18-year-old singer – who didn’t look too impressed with their performance.
Some fans were convinced she may have been poking fun at the pair, with one writing: “Seems Billie was a little rude” as another added: “Disrespectful.”
But while some were certain Billie’s reaction had something to do with the two women, others were quick to defend the Bad Guy hitmaker, as they pointed out that she may have actually been reacting to herself.
As the comedy queens took to the stage at the 92nd Academy Awards, Billie just so happened to appear on the big screens which are placed at each side of the stage.
And it seems the young singer became embarrassed as she spotted herself, causing her to make an awkward look.
Taking to Twitter, one fan wrote: “She was laughing along with everyone and then saw herself and was taken a little off guard, like, ‘What, why am I on the screen?’”
“I think Bellie Eilish is reacting to seeing herself on the screen, not the performance. Just my two cents. #Oscars,” another added.
Agreeing, another asked: “Are we sure she wasn't reacting to being the one in the camera shot? I mean, it looks like she's looking at a monitor and notices herself on it and is like, ‘Ugh, why are they looking at ME?’"
Seeing the funny side, others joked that Billie could join model Chrissy Teigen in the Hall of Fame for most hilarious Oscars reactions.
“Billie Eilish’s reaction to Kristen/Maya will be a meme in five seconds #Oscars,” one wrote.
We wonder how the singer will react to the idea of becoming a "Meme Queen"...