It looks like a rod for automatic stops on power feed to me. One end is attached to a lever at the headstock side and those little micrometer dials have springs on them. Looks like it’s just the other end that’s not attached.
We've all had it drilled in our heads enough we should know better, but I think people do it for pictures. It's a common enough sight in sale ads that that's the conclusion I've drawn from it.