Browser Tab Icon

How do I get an icon that shows up on the browser tab for my website? When I look at the tabs of different websites I have open, they each have icons (Homestead has its little house - "h" encircled; GMail has its red "M"). I just have an icon of a piece of paper with a folded corner. I also notice I don't have anything show up in the Websites Manager page at homestead.com. I used to - but I think I somehow deleted it. Now it's a grayed-out box with "customized design".