Here they are in working mode.
Here's how they look folded.
With them folded down, it's much easier to slip the bikes out without them catching the extended pedals in another bikes wheels/spokes. It makes moving them much more pleasant. I found them on eBay here.
To close them, you click the two metal tabs on both sides of the pedal. Pull the pedal outwards and rotate them down. To put them back in working position, click the two tabs. Rotate them back up and push them back towards the crank arm. Simple!