This is the prototype solution to enable second display showing different things on JB4.2.2 SabreSD.
Make use of Class Presentation provided by android to be embedded into Status bar.
When unlock the screen, the Presentation will show on second display.
Now, the solution requires one .mp4 video placed in root sdcard.
Of course, you may change it to show anything.
The attached Files are a layout xml file, a patch and a recorded video.
The layout file should be put into android/frameworks/base/packages/SystemUI/res/layout/ folder.
The patch should be applied to frameworks/base.git.
The recorded video shows the dual display demo as a reference.