It tells buyers that a film purchased in HD might later gain 4K, HDR, Dolby Vision, or Dolby Atmos on a compatible device, and that if a high-quality version isn't available now, it might be added later. On Prime Video, Dolby Vision and Dolby Atmos have been restricted to the ad-free tier since February 2024, which costs an extra $2.99 a month on top of Prime. Dolby Vision, HDR10+, and Atmos are app-only regardless, so a film that genuinely is a 4K Dolby Vision Atmos release can reach you as 1080p SDR stereo, entirely legitimately, because you opened a tab instead of an app. What I'd check before buying another new releaseIs a digital purchase still worth it? If your living room runs on an Apple TV 4K, I'd buy from Apple, because the app most likely to render your purchase properly is the one built for the box you actually use.