Not seen this before, or at least haven't registered it before
Maybe it's just a traditional style?
I mean it's basically a glorified cattle trough? yes? - suppose it saves water though
Is this technique done elsewhere?
From the Melton Assembly Hall in Melbourne
Watch from the 2 minute mark:
https://www.youtube.com/watch?v=i4SsduI8-w8
From the 2014 International Convention in Melbourne: