Little house on the ... paddock

Robyn and I were driving through the Northern Tablelands last Saturday, enroute to dusty Tamworth. I spotted this small house next to the railway line, not far from Uralla. I just had to stop and take some photos. Thankfully I had my 5D and tripod at hand.
There is something unusual about this house. I wonder if anyone can spot it?

House1 by Ozimax, on Flickr
There is something unusual about this house. I wonder if anyone can spot it?

House1 by Ozimax, on Flickr