My initial thought (which I could be wrong about) was that the back side was left crude enough that I think it wouldn't be seen when in use. For example on a lamp most parts can be seen, front and back, from some angle... where as on a chandelier, not so much. However, if this were a leg from a footed lamp, well you get the idea.
Is the protruding nub solid? No threads or signs that it might have been threaded and had a bolt broken off in it?
Edit: I know the suggestion that it could possibly be a foot (leg) might make one wonder about the angles, but my thinking is that it could have attached to a rounded piece (like on a footed planter) which would make the angles work. The loop May be just decorative, rather than functional, but it would be good to know if there is signs of wear inside of it.