Paula Forbes at Eater explains:
Oh hello creepy Japanese robot breastaurant: Robot Restaurant (that's actually what it's called) is in Tokyo's Shinjuku Kabukicho district, which seems to be some sort of nexus of naughtiness. And so naturally the place is just chock full of giant "sexy" robot girls.
It's also full of actual, real scantily clad women who seem to drive their giant robot counterparts around the restaurant like go carts. They also dance on the giant drink trays the robots carry.