It doesn't matter if i use root or user - i'm getting the same behavior which is different UI for the same user - this is what i do:

i'm executing the following command from a queen beecon widget:
bash /home/user/smart/scripts/Launchers/CarModeSelection
it runs as "user" - i verified that by adding this to the end of the "CarModeSelection" script:
id -un>/res.txt
when i execute the following from x-term:
su user -c "bash /home/user/smart/scripts/Launchers/CarModeSelection"

the output being written to the file is the same - "user", but the UI looks different (see photos) from the one displayed when executed from the widget.

the UI is of a utility i wrote in C# using GTK# which is being executed from the "CarModeSelection" script.