Asked this over at http://www.doombuggies.com but haven't gotten many replies, so I thought I'd post it here too.
I've never been on the ride myself, so would be thankful for the info.
According to this info http://www.faqs.org/faqs/disney-faq/haunted-mansion the elevator is made up of the floor, the paneling, and the molding with the gargoyles. As the elevator goes down, the walls with the portraits stay stationary. Then when the elevator has gone down far enough so all the portraits are exposed, the elevator then latches onto the once stationary portrait wall and pulls it down to reveal more of the wall at the top. Then it stops once it's all revealed. The End.
If I'm not mistaken, from what I can see in a few videos and pictures on the net, the paneling is in fact longer when it's finished stretching.
As evident in this photo: http://www.flickr.com/photos/missymazza ... otostream/
There's no info about the paneling stretching in the first link.
So, is the info wrong, or did I miss something?
Looking at pictures, an educated guess would be the corners of the elevator wall are in fact longer, and are hidden behind the corners of the portrait wall. (Looking at blueprints, I'm not sure if that is possible. Not sure if there is enough room at the starting point.) I also would think the paneling on the elevator walls are bigger pieces, which move with the elevator, with the lower half hidden just below the floor.
So, I'm thinking after the first stretch to reveal the portraits, and after the top of the ceiling is revealed, the gargoyle molding and the paneled walls are latched into place. Now the elevator [the floor, the corners and the BOTTOM wood panels (separate piece from the wall panels)] moves. As it moves the TOP of the corners (of the elevator walls) are revealed and the BOTTOM of the paneled walls are revealed.
Of course, that's just a guess. Does anyone care to enlighten me on how it really works? Thanks.