Nope, don't have a picture. Saw it on a trip couple weekends ago. This guy was doing his chain and then kicked something away from under the back suspension fork. We all went 'What was that'? He probably expected this and showed it to us with a big smile.
I'll try again:
Take a rod (thing you can wind a nut on). On one side of the rod you make some kind of foot so that it wont sink away.
Get 1 other piece of steel (or aluminium?)
On this piece of steel you place the nut so that you can connect the rod and the piece of steel.
On the opposite side you fix a low U-profile. This will fit your fork ( the thing that holds the back tire).
Now, when you want to do you chain you connect both pieces.
Place the bike on it sidestand and go to the opposite side of the bike.
Then the guy pushed the bike on his sidestand and frontweel. Then he placed his tool under the fork keeping the back wheel from the ground.
When he was finish he simply kicked it away.
And it can fit under you sadlle because it comes in 2 pieces.
I do think that the length is the tricky part and it migh take some experiments.
Really do hope somebody gets it know and can write down a decent explication in understandable English. I am running out of inspiration :-)))