The preview -- which aired during Kendall's appearance on "The Late Late Show" -- begins with Jenner putting on a Kylie Cosmetic's lipstick while talking in a confessional. Wearing a pink ombre wig, Kendall horribly applies a fire engine red lipstick and puts the product way outside the lines of her lips.
"Oh my god. It feels amazing on my skin," Kendall jokes. "It feels so f--king good."
While at dinner, Kendall shows her sister her new look on Facetime. "Oh my god," Kylie says through the phone and Kendall replies, "I'm Kylie."
"You look cute as Kylie," Kylie says. "It looks amazing."
"That's the weirdest thing ever, Mason," Kylie replies through the phone.
Later in the clip, Kendall seems to poke fun at her makeup mogul sister's lip color swatch videos, which often appear on her social media. Kendall, now wearing a pinky nude lip color, shows off the product she applied all over her arm.
"This is 'One Wish,'" she tells the confessional. "This is what it looks like."
It seems that the entire Kar-Jenner clan participated in dressing up as other family members. In the clip, Kourtney is seen in large, reflective sunglasses -- something her sister Kim often wears -- while momager Kris Jenner dons a Khloe-like wig.
The "Keeping Up with the Kardashians" Season 17 finale airs Sunday night at 9 p.m. ET on E!