I've stumbled upon an article that say skechfab with cardboard helped a cardiac surgeon save a life of a little baby. So first, Thank you for what you do, that is uber-mega-great!
Secound, I wish to use the cardboard, but I don't understand how to zoom-in and zoom-out with the cardboard.
The magnetic thingy on the cardboard does not do anything. is there something I'm missing?
Also, on your post: http://blog.sketchfab.com/post/94454676619/announcing-sketchfab-cardboard-aka-vr4all
you ask to add '/embed?cardboard=1' to the url. is there any meaning to the number? like '/embed?cardboard=2' do something?