Is category-icons what meta is using on howto?
I believe this component is for adding icons to category badges. That is, wherever you see the category appear in things like topic lists, title bar, etc. where it normally has a square with the category color and the category name.
Whereas the icons shown in the howto category are simply using the built-in Category Logo Image setting found in the settings when editing a category.
Thanks for clarification, in the mean time I found out that what I was asking is core functionality indeed.