This design is definitely for users who appreciate or are otherwise accustomed to using the Mac OSX dock. (But if that's not your cup of tea, I recommend the built-in Launch-Pad or Dockbert)
Currently, there is no automatic "extraction" of the actual App's icon (or other object's mime type icon). You have to manually set an icon with an existing .svg or .png image file for each launcher you add.
You can export an existing app's icon to an .svg file as follows: open an app with File Types app and then double-click on the icon, then the app's icon is opended in Icon-o-matic, and from there you can export the native HVIF into an .svg file.
If someone can provide code on how to convert (on-the-fly) from the Haiku HVIF or legacy to an svg or png binary data stream, then I could automatically extract in run-time. But until I know how to do this, you can do it by running the HiQDock and changing the icon (you can see this in action in the video clip linked above).
I think I'll post on the 3rd-party dev list for a solution for this issue.
By the way launchers (for now) are only added manually, and I have not yet implemented the Mac OSX dock feature of adding externally launched apps to the Dock and then giving the user the ability to "Keep in Dock" so that the launcher stays in the Dock permenantly.