Maybe its just camera trickery but it looks like they are placing the tv markers based on the ball's position, but the chain gang seems to be setting up a half a yard shy or so from where the ball actually is. On a fresh 1st and 10 the tv marker was right on the ball, and the 1st down marker was exactly 10 yards from that spot, but when I looked at the chain gang it looked like it was about at the linemen's feet and a full yard short from where the first down would be from the ball's position.
Not that it matters. Gotta quit letting these receivers run wide open.