Really Cool Effect at the Center Bar at SLS Las Vegas Hotel & Casino

I've been in this business working on all kinds of weird projects since 1985, so it takes a lot to fool me.  But this effect in the ceiling of the Center Bar at the SLS Las Vegas Hotel & Casino had me wondering for a while:

Did you figure it out?  

Hint: It's an illusion that only works from this angle.  

See this page for the solution.  I'll definitely be checking this out on my next Vegas trip!