After having set all our shops to portrait mode and beeing happy to see the content in the Webbrowser without breaking ones neck, we found out that this feature only affects the fairly used BrightSign items, not the content. The general topics discussions told us, what is missing in the documentation:
"The portrait setting doesn't actually rotate the content. It rotates any clock or time zone, any text zones, and provides a portrait layout. You have to rotate the image and video content yourself."
Paying money for such a bad documentation and such a lame web interface (with a lot of glitches and bugs) really makes me sad. There is even not an App to control content from on the road.