Board Thread:Support Requests - Getting Technical/@comment-28602918-20160914083539

When I add a web page to my favourites in my browser, if they have an avatar it will be displayed. Such as in these examples:

So my question is, how can I do the same for my wikia?

The one on the right, the Harry Potter OC one doesn't have one. So if anyone know and would be kind enough, could they tell me how to go about editing it so I might add one to it as well?  