Witherspoon, who stopped herself from sharing too many details from the upcoming season, said that her character Madeline Martha Mackenzie will be seen throwing an ice cream cone at series newcomer Meryl Streep who portrays Mary Louise Wright, the mother-in-law of Nicole Kidman's Celeste Wright.
Host Jimmy Fallon presented to the audience photos from the scene which feature an angry Witherspoon gearing up to throw the ice cream cone at Streep who is walking away with her back turned.
"This might inform you about our relationship in the show," Witherspoon said. I really hucked it at her, y'all," she continued. "I nailed it."
Big Little Lies Season 2 is set to premiere sometime in 2019 on HBO. Witherspoon, Kidman and Streep will be joined by returning cast members Shailene Woodley, Iain Armitage, Zoe Kravitz, James Tupper and Laura Dern.
Witherspoon's Tonight Show apperance also included the actress discussing her new cookbook titled Whiskey in a Teacup and a round of Lip Sync Charades with Witherspoon teaming up with Fallon to take on Zoe Kravitz and her rockstar father, Lenny Kravitz.
Witherspoon and Fallon won the final round of Lip Sync Charades after Witherspoon correctly guessed that Fallon was mimicking the song "Don't Speak" by No Doubt.
Witherspoon's cookbook was released Tuesday with the Hollywood star posting on Twitter a short video of herself holding up the book with hearts in her eyes.