The live feed is indeed live, and has sound (but no color), and it shows the interior housing area of the Amur Leopard's habitat. This is where they sleep (during the morning hours, usually) and retreat to when something's going on outside that they don't like. It's also where they sometimes drag their food.
I've been watching them for a couple of days now and wanted to share; this is a species on the verge of extinction in the wild, for one thing, so it may be that we're watching two of a creature that will soon be gone forever. There are some left in zoos, though, like these, so it's not completely hopeless! For another thing, they're both ADORABLE. The mother leopard is quite the good mom, and she spends a great deal of time cuddling with or washing her cub and generally seems very careful around him. I watched her for a good twenty minutes wanting to get up, and constantly starting to move, then glancing down at her sleeping, cuddled cub and stopping. She wanted to move but didn't want to disturb her kitten

Right now, they're both visible, and for the first time since I've started watching, the door to their cage has been shut--I assume the zookeepers are washing up the habitat or something. Mom seems annoyed and is scratching at the door, and her cub's sort of huddled in the corner. Usually, though, they're both quite relaxed and happy, not to mention very healthy-looking.
Enjoy!
(Still shots from the webcam:)