That is an excellent question, isn't it?

[ He leads her onward, away from the elevator, across deck, to the domed CES; this he opens with his signet ring, a lion's head in gold. A meadow, probably somewhere in the Tyrell lands, he thinks, dotted with wildflowers. ]


[ But he closes the door once she sees it, and then taps his ring to the lock. ]

Now you open the door. The lands it shows you will be yours. From your world.