In my role as a tutor I often have to set up test Ubuntu installations to help students that use Ubuntu - I myself use Windows (sorry!).
For convenience I always install xrdp, and I found out by Googling and lots of experiment that I need to also install xorgxrdp. Then I can RDP to the test installations from my Windows workstation and this all works very well.
If I don't install xorgxrdp my RDP session just shows a blank screen. There are lots of questions about this already, and I vaguely grasp that xorgxrdp is an interface between xrdp and xvnc, so I'm not asking how to fix the blank screen. Instead I would be interested to know what exactly has happened if I make the connection without installing xorgxrdp. The connection has obviously established some form of graphical session because the mouse works, and I see the Ubuntu cursor in my RDP window not the Windows cursor. Can I do anything with this connection? Is there any way of running a graphical application?