When you share a link from The Globe and Mail to your Facebook wall, you get a little custom icon (maple leaf) next to the "Like" button, instead of the usual general page icon. Looking at the Facebook page source, you can see that the icon is stored here.
However, going back to the Globe and Mail page and looking at its page source, it's not clear where this icon is actually coming from. At first I thought Facebook was grabbing the site's favicon.ico or iPhone icon. But if you compare the icons, they are clearly different both in color and in shape, not to mention size.
Is this something Facebook has done on its own end? Or is this something any webmaster can control for his own website?