As far as I know, my questions in this post have no importance.
I will post four screenshots. The first two are from article comments that I saw while browsing TidBITS (where I cannot add a comment); the second two are the same comments but viewed from TidBITS Talk. The reason I’m posting is because of how the user identification varies. Note the change in the icon, and the changes in the text identifiers. (How would I correctly label the two user identifiers? “David C.” is constant, but the other one is variously absent, David0, or Shamino.) Why does the icon change, and why does the second identifier change?
Finally, why is the second screenshot’s article title so much bigger than the others? It does not appear that way when I look at the screenshots on my Mac.
Thanks for any enlightenment.