Setting up mirror displays with dbus (ApplyMonitorsConfig)

Hello people,

I am attempting to set up mirror displays for two monitors with dbus.

My current understanding is that mirror display can be accomplished if two monitors have the same logical monitor setting (x, y, scale, transform) and have similar modes (say, one has a mode of 1920x1080@60, and the other one has a mode of 1920x1080@60.01). If this understanding is correct, I can set up two monitors to be mirrored with the ApplyMonitorsConfig method from the org.gnome.Mutter.DisplayConfig interface.

I experimented with this approach, however, I am getting an error: ERROR:root:Failed to apply monitor configuration: org.freedesktop.DBus.Error.InvalidArgs: Logical monitors not adjacent despite having two logical monitors have the same x and y position (x and y are all set to be 0).

Is my approach to setting up mirror displays correct? I have a feeling that ApplyMonitorsConfig is primarily used to configure displays in joint mode.

I am fairly new to this topic; any insight is much appreciated!