KIM Kardashian has left fans baffled with an optical illusion during the season four premiere of The Kardashians.

The reality star, 42, jetted to Cabo San Lucas, Mexico, with her sisters Khloe, Kylie, and Kendall during the episode on Thursday.

Kim Kardashian left fans baffled with an optical illusion during the season four premiere of The Kardashians
5

Kim Kardashian left fans baffled with an optical illusion during the season four premiere of The KardashiansCredit: Hulu

It looked like she had 'tiny arms and shoulders' because of the black shawl draped around her
5

It looked like she had ‘tiny arms and shoulders’ because of the black shawl draped around herCredit: Hulu
On one of the final nights, the girls, their mother Kris Jenner, and Kris’s boyfriend Corey Gamble enjoyed a lavish dinner outside.

Kim wore a tight blue tank top and shielded herself from the evening chill with a black shawl around her shoulders.

Her coverup baffled fans, however, as it gave the effect that she had tiny shoulders.

One Kardashians viewer shared screenshots of Kim on Reddit and wrote: “Proportions are way off? Huge head and tiny shoulders?

“Once I saw that, I could barely concentrate on the T-Rex attack on the vittles.”

Another commented: “It’s the black sweater vest draped around her shoulders.”

A third admitted they also got caught up in the illusion, posting: “I saw it as tiny shoulders too, till I noticed the sweater!”

Elsewhere in the episode, Kim, Khloe, Kendall, and Kylie soaked up the sun by their huge villa’s pool.

The siblings wore tiny string bikinis and posed for a series of “thirst traps.”

They were not joined by the eldest Kardashian sibling, Kourtney.

Kim and Kourtney have been feuding ever since the Skims mogul partnered with Dolce and Gabbana following her sister’s wedding.

At the start of the season four premiere, they had an explosive fight after Kim rang Kourtney to extend an invitation to a dinner with the fashion house.

The Lemme founder, who was heard on the other line, said that she was “Dolce’d out” following their drawn-out fight over the Italian brand and wouldn’t be coming.

Things got heated when claimed Kourtney’s wedding fashion wasn’t “original.”

Kourtney said: “You’re talking about the bulls**t details because it’s all your egotistical, selfish mind can think about.

“You cannot stand someone else being the center of attention. You came to my wedding, you couldn’t be happy. You complained from the second you got there until the second you left.

“Forget about you couldn’t be happy, you couldn’t be happy for me. You couldn’t be happy that I was the center of attention and you weren’t.”

Kim broke down crying, asking her sister, “Why [do] you hate me so much?

“You have a serious vendetta. You hate us. You are a different person. We all talk about it.”

Kourtney hit back: “Because I don’t need you guys anymore. I don’t need to be a part of it.”

She then accused her sister of being “a narcissist,” saying: “It is all about you. Anything you do, it’s about you and how it looks to the world about you.”

Kim jetted to Cabo with her sisters Khloe, Kendall and Kylie
5

Kim jetted to Cabo with her sisters Khloe, Kendall and KylieCredit: Hulu

The sisters posed by the pool for sultry photos
5

The sisters posed by the pool for sultry photosCredit: Hulu

Kourtney and Kim had an explosive fight at the start of the episode
5

Kourtney and Kim had an explosive fight at the start of the episode