Dual Drive?

my friend andy sent me this...

dual drive?
explain please...

I can understand having the chain rings on both sides for an easy flip flop sort of conversion
yet I am not sure if swapping the chain would be faster or easier than flipping the wheel

yet
this appeared on the SLIPPERY PIG site
it may be yesterday's technology
trying to just get our attention

on a similar yet different sort of dual drive on the bicycle sort of tip...

front and rear wheel drive on a full suspension mountain bike from Christini
official site www.christini.com
all wheel drive motorcycles
all wheel drive bicycles
not sure if this ever caught on in the bicycle world
it could be the best thing ever
but I have only seen one demo bike
and that was several years ago at a Snowshoe event