No, it's a sort of decorative structure on the knoll itself. That said, yeah, I've read the Warren Report in its entirety, and you cannot, if you have a lick of sense, do that and come away with any doubt that Oswald did it. Alone, because he wasn't a People Person.
That said, this is one of the conspiracies that I can make work using the information contained in the Warren Report by just making a few minor tweaks, and it's so much simpler than shooters at other angles. Just put the damn conspiracy shooter in the window of the Texas Schoolbook Depository and Oswald in the lunch room where he said he was.