Kylie Jenner -- Most Shocking Photo ... This Really Is Her! (PHOTO)

Do NOT trust your eyes ... this IS Kylie Jenner going deep, DEEP undercover on Monday without a lick of makeup, and what appears to be her real hair.

KJ was out car shopping ('cause one Ferrari's never enough) in Calabasas, and what an incredible difference a few days makes! The pic on the right is Kylie at NY Fashion Week.

The 18-year-old is now the reigning popularity queen in the fam, but we can't recall her rocking such a natural look in public since her pre-teen days. Nice to know Tyga's GF can still look like she's 18 every now and then.

Although we doubt he sees it that way.