Apple TV 4K screenshots now supported.
For compatibility with the new Apple TV 4K, iTunes Connect now supports screenshots that are 3840 by 2160 pixels. You can upload them during your next version update or when your app has an editable status.
Regardless of resolution, the screenshots you provide for the App Store on Apple TV will be displayed on Apple TV 4K and earlier models of Apple TV. App previews in this size are not yet supported.
Learn more about building apps for tvOS.
Get details on how to upload screenshots.