"The Entertainment" was a video tape in the book that "so entertaining to its viewers that they lose all interest in anything other than viewing it and thus eventually die."

Depending on your scholarly beliefs, it's either just a metaphor for addiction, or in addition, a critique on media and media consumption. I chose to believe the latter, in that it could stand to be a critique on how our pastimes are intentionally becoming more engaging and addicting.

I'm not sure on the visual representation, but the thing would have been a Rauchenberg-ian collage of video, text and audio, layered together and becoming more "recommended" for the user, based on physical cues from the physical input devices, as well as choices. The actual recommendation algorithm would have been relatively primitive, most likely a decision tree, or if I could figure it out, an ensemble algorithm that would have created better media recommendations in real time to show to the viewer from trending topics, imgur, youtube, that type of junk.

The samizdat refers to a film (after which Infinite Jest is named). This film is so entertaining that, once seen, a viewer will want to do nothing but continue watching it, endlessly.

(Also, IJ is a great novel.)