lululemon-illusion

An illusion yoga pants created causing a flat booty-ed person's back side to appear more curvy and voluptuous than it would in normal attire.

note: lululemon is an athletic brand that specializes in yoga pants

Chet: Dayum I didn't realize Sara had such an ass on her!
Chad: Nah man! It's a lululemon-illusion! That girl's ass is flatter than a pancake.