Size and layers of tvOS Large App Icon

Hello,

I have come across a number of inconsistencies and questions about the large app icon in tvOS Xcode projects:

• The Apple tvOS human interface guide says, the size is 1280px by 768px, and there is no focus or safe zone (as opposed to the small app icon). So it is not focusable.
• If you create a new tvOS Xcode project from scratch, the default large app icon contains 3 layers - why is a parallax image needed when the icon is not focusable?
• Elsewhere on the internet I have seen reports where people say the large app icon requires at least 2 layers.
• If you look at other apps on the Apple TV App Store, a large backdrop is shown with the app, with the description in front of it. However, this image is 1920x776 (I took a screenshot and measured it) which differs from the size in the HIG.
• Clearly the app's backdrop image in the App Store is not focusable. Why then require at least 2 layers?

Does anyone here know exactly how the large app icon is used in the App Store? I cannot imagine it is simply stretched from 1280x768 to 1920x776.

Also I can see from other apps that the large background image has the motive on the right side while reserving some space on the left side for text.

Is there a way to preview the app how it looks like in the App Store?

Also, why does the app icon require layers if it is not focusable? (that is, if it is indeed the large image in the App Store)

Thanks for any answers on all this. I have the feeling I have missed something important...