The children are thinning out, and Mr. Wonka is well aware of it.
They're all getting tired, so Willy leads them to the elevator. But it's no ordinary elevator: it has thousands of buttons all over the walls and ceilings.
And, Mr. Wonka tells them, the elevator doesn't just go up and down, it goes in every direction. And because it's made of glass, you can see everywhere you're going.
Mr. Wonka tells the children that they can pick any room they want: from "THE ROCK-CANDY MINE-10,000 FEET DEEP" (25.14) to "RAINBOW DROPS-SUCK THEM AND YOU CAN SPIT IN SIX DIFFERENT COLORS" (25.28).
Mike Teavee picks, surprise surprise, "TELEVISION CHOCOLATE" (25.32).
He presses the button and suddenly, they're off – sideways! Everyone falls over and is pretty scared because it's going in all directions (oh, and because Willy Wonka tells them there's another elevator that goes in the opposite direction on the same track.)
From the elevator, though, they can see some fantastic things: a mountain made of fudge, a lake of caramel, a village of Oompa-Loompas... the list goes on.
Finally, the elevator comes to a stop, and they get off; but not before a warning not to touch anything in the television room. It's quite dangerous, in fact.