I noticed you posted this at the Ubuntu Forums
as well. I would have replied there, but seeing there were already other suggestions or approaches from others...
Anyway, if I understood your question correctly, you wanted to see it in action by showing you the actual messages that gets displayed inside a terminal window when you run it directly from the desktop. If this is the case, there's an existing thread that exactly addresses this. The general idea is if the script is run from an already-open terminal window, it will just execute the commands one after the other. If the script is run directly from a GUI, it will open a terminal window first and then run the commands.
You'll find the discussion here
. The TL;DR version is here
. Don't include the xfce4-terminal
line. Just add the 3 sudo lines after # YOUR CODE GOES HERE #
HTH. Post back if it addresses your issue.