You may choose to display your digital signage content vertically rather than horizontally using your ChromeOS devices.
You can set the orientation of your ChromeOS devices directly from within Google Admin.
Navigate to Devices > Chrome Management > Apps & Extensions
Select the Organizational Unit you'd like to edit on the left
Click the "Kiosks" tab > click TelemetryTV Media Player to open the modal on the right.
At the bottom, edit the "Screen Orientation" setting to 90 degrees, and click Save.
This setting will apply to all devices in the organizational unit, so you may choose to create a separate organization or sub-organization for your portrait screens.
☝️ Pro tip: Build playlists specifically for portrait screens using TelemetryTV's Playlist Configuration feature.