There used to be an SBS program that aired late Saturday nights called Eat Carpet (on wayback). It featured a handful of short films each week and was standard viewing for me for quite a few years after I finished Uni.
I don't know exactly when it was, but it was on Eat Carpet that I saw the best animated short I had ever, and still have ever, seen. After that I would often watch Eat Carpet just on the hope they would show it again. The animation itself was good -- the movement, sound and mood where all perfectly matched -- but I think it stuck in my mind mostly because of its poignant comment on the human condition.
For some reason that animation popped into my head today, so it was time to stretch my Google-search skills and see if I could find it. The combo of "short film animated four men box" finally did it. Which is lucky because it turns out it contain five men, not four.
Good old internet. And on You Tube too, so without further ado: