I had two websites I placed on my home screen from Safari that had no icons. Magically they've recently appeared with icons....one the Apple symbol and the other a Tim Hortons symbol. What's with that???
probably means that the web masters of those sites have updated them. They can load iDevice-friendly icons onto their sites so that they appears as "real" icons" when you save them. I can't remember the name of the coding at the moment (too lazy to look it up, sorry ), but it's the same way web pages show icons on tabs in browsers like Firefox. The web site owners have done that.