Kendall put on black heels while mom-of-three Kourtney, 36, went barefoot to exasperate their height difference. Without footwear, the Calvin Klein model is just shy of 5'11", while the eldest Kardashian kid tops out at 5 feet.
Even mom Kris Jenner got in on the joke, regramming Kim's photo with the caption, "Not sure how this happened but I gave birth to both of them ... #legs #love #familyfun #beautycomesindifferentshapesandsizes #blessed."
After the shoot, Kendall showed off her hair skills in a "3 snaps we out pony" move.
Even though Kendall is doing very well in her modeling career (just look at those long legs!), she admitted to Allure that after battling acne in high school, she's still working on her self-esteem.
"I still have a hard time looking at someone when I'm talking to them, and I get nervous," Kendall told the magazine. "When I started getting in front of the camera a lot, I think my confidence started to come out. It took a minute, because I had to believe in myself."
The youngest of the Kardashian krew, 17-year-old beauty chameleon Kylie Jenner, also deals with insecurities. She recently revealed that she gets temporary lip fillers, frequently changes her hair color and just tried out lighter contacts for a new look.
Watch Kylie's admission about her famous lips in the video below.