Custom icon on custom assets

2D
1

As mentioned to another post, I develop a sprite based atlas tool with some extra features.

I wanna deeply integrate my resulting atlases into Unity3D thanks to AssetPostprocessor.
Everything works quite properly.

Now I need to make a clean integration, by defining, for example, some custom icons for my custom assets in the Project window.
But I can’t find a way to do it ? It doesn’t change the world, I know ^^

2

Kind of a duplicate, but in any case, you can achieve it:

I’m still trying to figure out how to change that icon in the inspector though…