Xrdp - How do I connect remotely to an existing local session?

Solution 1:

xrdp works internally by opening a new X session and controlling it through Xvnc.

Xvnc is the X VNC (Virtual Network Computing) server. It is based on a standard X server, but it has a "virtual" screen rather than a physical one. X applications display themselves on it as if it were a normal X display, but they can only be accessed via a VNC viewer

But this is just the default settings, there are other options that you can use:

In particular the option vnc-any also allows you to connect to any reachable vnc server:

So if you want to connect to an X session running on your regular monitor(s), you can install a regular vnc server and connect to it through xrdp.