X-Ray is perfect for the times where someone new to a series tries to watch without starting from the beginning of a series and knows nothing about the characters. This feature also offers information on cast members so when you recognize a face, but can't quite place what an actor was in before, that data is right at your fingertips. Incidentally, Amazon owns IMDb. Apple TV owners who use their device to access the Prime Video app can now access the X-Ray feature as well.
Accessing the X-Ray feature is accomplished by hitting the pause button during playback. In addition to the characters and cast tabs, X-Ray also offers information on the music in the series, photos, trivia, videos, and other bonus material. X-Ray isn't supported on all content available via Amazon, and there is no way to know if the movie or show you are going to watch supports X-Ray. However, all Amazon Originals, like Man in the High Castle, support X-Ray features.
The updated Apple TV app is said to be in the process of rolling out to all Apple TV users meaning if your app lacks the feature, keep checking for updates. Amazon Launched the Prime Video app for Apple TV users in December 2017. Reports indicated in 2017 that Amazon was preparing an ad-supported version of Prime Video, but that hasn't landed yet.