That's a good reference for what orthographic rendering is, but if you look at the rendered scene it's definitely not orthographic. Parallel lines in the model converge towards the camera when the model is viewed from an angle.
I think it's an optical illusion. It looks weird to me, but comparing it with various objects I have I do feel like they're parallel.
Specifically the roof edge vs base edge, the back of the roof vs the front of the roof.
Probably better to use perspective as the default like Sketchup.