Handreared Koalas are fairly simple to keep - just give them a tree trunk and they'll sleep for around 20 hours every day, or more. When they're awake they're only interested in one thing, food. So if you've got fresh leaves in a pipe attached to the tree, the Koalas are happy.
And on weekends they get to meet the public.
Admittedly, this area looks a little spartan. Most places give koalas several tree stumps/trunks to climb on, some even provide small non-eucalypt trees. However, have alook at Taronga's new Koala Encounters enclosures and you'll see they are smaller and more sterile than this one. (I should also point out that Taronga's koalas periodically get rotated through different enclosures, some off display). The basic requirements are the same.
This koala yard is in the same aviary as the other Koala yard, the fenced pathway separate the two. The other yard is less than half the size of this, but looks better 'coz it's got lots of long grass.