finder – include an icon in .app * hack *

I've recently learned a "hack" for creating an .app file from a folder containing an application with resources. This has been explained here.

The main folder receives the same name as a bash script at the top level of the folder system, except for the folder name that also includes .app

What I'm wondering, however, is it's possible to configure this app to display an icon that I provide when the file is viewed through the Finder. Or can it be done by making my file system a Bundle?