I am depending on all of you streetlight nuts to figure out who made this odd luminaire. There has been speculation that this might possibly be a Spaulding or a Joslyn luminaire, but it is still not offically confirmed yet. To me it looks like something that doesn't know how to express itself other than a strange expression;-) The city where this light was located still has several of those lights here and there.
Another view of the same luminaire, complete with its arched mastarm.