Great spotting, Paul. Given the unusual placement of the subject right at the edge of the frame, cut off at the legs , I thought the OP must surely have compositional concerns, so I never even bothered opening the image on anything except my cell phone. However, when one does, the technical problems with the composite that you observed couldn't be clearer.
That being said, and not that there is anything wrong with the current composition (...in fact, I rather like it...), IMHO, there still could be an interesting discussion of conventional vs unusual subject placement.
T
PS - BTW, I've attached a version of the cropped image small enough to avoid a potential side-track into a discussion that the artifacts we now all see might have come from the forum's compression software.