Mira currently works with screens that already support content rotation. You will need to set the screen's display mode to Vertical or Portrait in its settings. If your display does not support content rotation, Mira currently delivers content exclusively in landscape mode.
We're working on adding support for delivering content in both portrait and landscape mode, with the ability to switch between layouts at will; this feature will be included in a forthcoming Dashboard update.
If you plan to use Mira with vertical displays, please contact us for support.