Ebon2007 does have a valid point if he is using a PC that came configured such that Window 'hides the file extensions in explorer for known file types'. This is a common situation of which many people aren't aware.
Many of our downloads are .zip or .rar files, and, if you had such a machine, Windows would launch an archive utility program (if there was one on the machine) rather than a comic reader program.
I don't think it would be the easiest to do the programing to add the icon to all the pages where the files are listed (maybe it is, but I am not a programmer), but maybe we could add a FAQ piece on what to do to turn off the Window extension hider, and how to rename files.
Users seem to run into this a lot, and often aren't even aware that zip's and rar's can be simply be renamed to be accessed by the readers.