Rich, you might be right, but the "hay pitchers" that I've seen didn't have what appears to have a "safety railing". 

My guess is it might be a portable scafold with the walk boards missing.  The cables that lead up and over the top seem to be anchored at the hitch so that the "basket" remains at basically the same angle, or I might not be looking at it right, dunno.

Might have been used in building/shingling old barns or houses. ??