The screen arrangement is not the “layout” of the content. It only defines the physical arrangement of the screens onto which the “layout” will be overlaid. The screen arrangement will almost always mimic the physical arrangement (how they’re mounted to the wall).
For example a single video could span across multiple screens and depending on the arrangement and layout, only portions of the video will show on each screen. Alternatively the screen layout could have zones that fit perfectly onto the screen arrangement enabling separate content to play on each screen.
The example below shows a non-standard screen arrangement. Beside the example arrangement is the screen layout which is a single zone filling the entire canvas. Only in the areas in which screens have been defined will the video playback. The video will be “cut-out” in areas where there is a zone layout, but no screen defined.
If a media asset (video/image) is programmed to play in this single zone, the sections without the screens defined will be cut-out. Below is an example image with playback results using the above arrangement example and single zone layout.