Alfred Brehm house

The newly renovated Alfred Brehm house still looks like it needs a major overhaul...

Does the garden in the middle hold any animals?

It's probably the only nice enclosure in the Alfred Brehm Haus and is a very nice walkthrough with a variety of free-flying birds and flying foxes.

Ah, I've seen pictures. Yes, it does look nice!

Yeah, for indoor cat enclosures, I believe the lions and tigers have it good, in a bizarre way.

Yes, those didn't seem bad. Though the central walkthrough part was the only enclosure in this building that I actively liked.
(Though although I didn't like most of the enclosures, there were lots of really cool species that I would of course not want to be lost!)

And we shall also continue to disagree

The indoor moated enclosures are good relative to many big cat indoor enclosures in Europe, but as I hope LD will confirm, on the day of our visit the Lion's indoor enclosure was their only enclosure, as the medium sized outdoor moated enclosure (which are good) on that side had tigers (Malayan?) in it. And although on the other side both the indoor and outdoors had tigers, I've got a nasty suspicion they were different groups.

The splitting of the ABH's outdoor and indoor exhibits makes bad enclosures worse and good ones bad.

Having said all of that, zoos over this end of the world have really given me a different scale for judging exhibits, I suspect I will be a lot kinder the next time I am in Berlin!

What is that circular thing in the middle of the room? Is it an animal exhibit of some kind?

No; it's a decorative fountain.