Displaylink has an app that can be installed in Android to attach a second screen to an android system. This mirrors the screen true the displaylink docking station to a screen attached to the docking station.
I curious if this is seen as second screen in the multi-display SDK from android. https://source.android.com/docs/core/display/multi_display
Because if so, you can also build an app that uses that second screen (true Displaylink) to present a second window.
Does somebody know or tested this?