I managed to show my desired icon, here are my notes for configuration:
- Open RDP connection to TWX server.
- Open folder: D:\Apache Software Foundation\Tomcat 8.5\webapps\Thingworx\Runtime (assuming Tomcat is on D: drive)
- Copy your file ("DSPLogo65x75.png" in my case) into this folder
- Open file "index.html"
- Add in front of head tag: <link rel="shortcut icon" type="image/png" href="DSPLogo65x75.png"/>
- Restart Tomcat (sometimes not necessary, test before you restart)
I attached a screenshot of how the file looks like in my case.
However, I am not sure if this is the "proper" way to do this but at least it works.