Favicons are handled differently by different skins, so there isn't one answer to the question of how to make them work.
In my skins, I take a consistent approach to it. You can create a
res folder in the project, stash your favicon there, like
wardicon.png, then tell the skin (on the
Misc tab), to find the favicon at
res/wardicon.png.
My skins are not bundled with jAlbum, so you have to install whichever one you want to tinker with:
https://jefftucker.jalbum.net/skins/
Laza's skin, the bundled ones, take a very different approach. Best if you post a question about it in the forum section for the skin you're trying to use.