Even after you change the icons for your RemoteApp published programs on the RDSH servers, your icons on RDWeb may not change. This happens because RD Web server caches the icons as images. If you delete this cache, the icons are downloaded again from the RDSH servers…the next time someone launches any RemoteApp.
Here is what you need to delete on your RD Web server:
If, even after the cache delete, you do not see the icon, try this little trick:
Either remove and re–add the published application or change the published application’s alias.