This indicates the video was sourced directly from a streaming service (WEB-DL) and then "remuxed." A remux takes the raw video and audio streams without re-encoding them, preserving the original quality while changing the container (often to MKV).
The second episode, titled originally aired on January 29, 2018. The Alienist 1x02 WEB-DLMux Ita Eng 5 1 Earine
The Alienist Season 1 Episode 2 Review: A Fruitful Partnership This indicates the video was sourced directly from
This paper covers the technical and narrative details for the media release titled This specific file represents a high-quality "multiplexed" (Mux) version of the second episode of the psychological thriller series, The Alienist . Release Specifications titled originally aired on January 29