The Mobile Signage stands up for your message.
One can just as easily have the screen in the popular portrait format.
It is the same orientation used in handheld devices such as smart phones and tablets.
Moreover, it is more or less standard when it comes to digital signage in public spaces.
InstallationFree of course with a writing board of the highest quality on the back.
You can, of course, choose to webcam (attached to the top edge) and starter set with pens and erasers for the board.