If you have a multiple monitor setup with the same type of monitors, there is no way to see which monitor is which (except by using 'Identify Displays'). I would like to see in the Display dialog to which output port a monitor is connected too. For example output, see xrandr --listmonitors which returns something like '0: +HDMI-A-0 1920/518x1200/324+1080+480 HDMI-A-0'. So I would like to show 'HDMI-A-0' in the Display dialog. Unfortunately I am not sure about the best place to add this, so what do you think? E.g. we could add the port to the display_name in the combobox ('DELL P2414H on HDMI-A-0', or add a 'Port:' label under the combobox that only contains the port or add the Port information only as a tooltip of the combobox.
To be honest that feels a little like TMI (too much information). Why would the average user want to know/see this information? I mean: how many displays do you have connected on a regular basis that you keep changing the connectors for so this is relevant enough to *always show*. As with https://bugzilla.xfce.org/show_bug.cgi?id=13285 I would say the identification popups should suffice for now.