But, then I install this extension to set up favicon. Just works!
But, still I don't know the function with 128, 64, and 32 resolution coz the only working resolution for update is 16x16.
However, it's still a 5-star extension!
The larger icons are really for windows/internet explorer users.
If you were to drag and drop the URL from the address bar (in IE) to your desktop, windows would use the favicon as the icon of the shortcut on your desktop. If the only icon is 16x16 - the resulting shortcut would look ugly because the favicon would be stretched.
The larger icons gives windows a choice of which resolution to choose when creating the shortcut.
It's not a function many people think about, but it's a nice touch - and that's why I added it. You don't have to use it - but it's there if you want to use it.