I am having problems on a book I am writing on iBooks Author using the Contemporary template. I did add an Image Gallery widget in landscape orientation, but it doesn't appear on portrait orientation.
Anyone knows what happens on portrait that it doesn't show the widget?
I found that you can only view the Gallery Widget in portrait mode if it is on a "page" not a "chapter" or "section" screen. It behaves differently though, it shows up smaller then goes fullscreen when you click on it.