Miranda Kerr: Snapchat THIS ... My Giant Diamond & My Looong Legs (PHOTOS)

Miranda Kerr damn near upstaged her own engagement ring from billionaire Evan Spiegel by stepping out in a VERY mini dress.

The model debuted her new rock Saturday night when she and the Snapchat founder hit up the Shore Bar in Santa Monica. Don't get us wrong ... the round-cut diamond is big and impressive -- Evan's worth $2 billion, after all.

But those legs ain't too shabby either.

It's kinda like a logic formula -- THESE will get you THIS.