Mini Icons in Firefox Bookmarks Menu?

Hi, I have recently switched from using Safari as my everyday browser to Firefox. So far so good mostly, however one thing I miss is the little mini site icons that appear next to every site name in Safari. I didn't realize how much those help in identifying sites in a long list until I changed to Firefox, which does not display the mini icons in the Bookmarks menus. Now strangely, when I bring up Firefox's Manage Bookmarks window, or the Bookmarks sidebar, the lists there do show the mini site icons, just as I want! But for some odd reason, the Bookmarks drop-down menu does not display them. Is there some way I'm missing to turn on that functionality, or a plugin that does it? Thanks.