The thermometer means that the file has got a comment. Green = excellent/good , yellow = fair, red w/ bug = corrupt/invalid/fake. Makes sense see
On the shared tab, you look for the file and it lists how much you've uploaded for the file "Session (total)", for individual people -> second button, show details on them in your queue/source list.
Infact, I think you haven't realised/spotted about the showdetails feayure? It explains all the icons and shows stats and details either about clients, or if you go 2nd button-->file details on a file it shows u info, like comments on them
Does this all stem from Mac only having one button by any chance? Forget those primitive 1 button days
/me hands krug a two/three buttoned mouse and hides
