The picture with the flag makes it look like there was empty space, but it was taken before the concert started. By the time it began, not only was the pit area full, but the seating areas on the sides (where I was, by chance with a good view of when they snapped the one with the flag) were...
Yes, it's best to block and ignore the troll(s). It's either true trolling, or sincere mental illness. Either way, it's sad but there is nothing to do but ignore.