No one has the responsibility unless they are being paid. As of this time, it’s a volunteer position.
I'm going to disagree with you a bit here, Mike, and let me go outside of the inbred world of slot racing to make my point.
I've become more and more involved in 1:1 collector car events in the last couple of years and have often agreed to serve on the committees who put on such events, as was the case for this year's Tigers East/Alpines East 35th annual East Coast United 35 event.
At the event's first organizational meeting, the committee chairman listed the tasks that needed to be performed and each one in attendance was delegated a particular task, with their concurrence of course. I agreed it was to be my responsibility to put on the parking lot slalom for United 35. And no, I was not paid in any way and purchased some of the items we needed for the slalom at my own expense (even had to pay to attend the event; our budget was that tight). But because I agreed to do it, it was my responsibility not to disappoint the roughly 35 owners who paid to enter their cars in the slalom event on Sunday morning.
That's the way it has always been in the volunteer activities in which I've been involved: Scouting, marching band parent, church choir member, etc. If you are asked and you agree, say, to man the concession stand stand at one football game each month, it is indeed your responsibility whether there is compensation involved or not.
The guys doing the race reports and pictures haven't, by and large, been asked to take on those tasks. They assume them on their own volition because they feel it is important, to further the hobby they enjoy and perhaps even love.
I won't say any more, but I think at the big races the folks running the show should make it a priority to ask people to take on those tasks, to delegate them to make sure they get accomplished. It's happened to me, i.e. a race promoter has requested I come to post race results and to take pics. And, yes, there is sometimes a bit of compensation, never money (so far) but often housing and few meals.
BTW, although Noose, Bill, and Bryan have carried the flag far beyond what he started, I wonder if anyone recalls just who first began posting top, bottom, and body pics of all the cars at the early Retro races. As far as I know, that had never been done before in the history of the hobby: every car entered at a race event photographed for all to view. If I could just recall the guy's name...