This is what the Secret Lair (aka '73 Winnebago) looks like. Sorta. It actually has four walls and a roof, not to mention it's not smaller than the '70s era model lady that is unfortunately cropped in the picture.
But, the layout is indeed the same. Feast your eyes and imagine living in the space and loving it!!!
Update: Since I'm getting a lot of new traffic (thanks, C&L) I wanted to reference this post that explains the whole Secret Lair thing. Kinda. As much as anything in my life can be explained, anyway.