I ran into this strange problem where a new published app was created, publishing a webpage. The default IE icon was given to the published app.
I then proceeded to update the app with a new icon, this new icon was registered in the Citrix Management Console as expected, but when I went to the PNA or the WI, the IE icon was still there for the app.
The cause of this problem is something to do with icon caching. There are apparently some registry hacks, and some icon cache folders to be delete. This is a bit hit and miss. They method that works is to actually delete the old Citrix app, recreate it, and select the new icon before finalising the app’s creation.