A video explaining why analogue horror works and why it is so effective, especially 14-18 minutes in where there is a very good description and review of a video featured later in this post:
The word analogue is defined as: 'relating to or using signals or information represented by a continuously variable physical quantity such as spatial position, voltage, etc' or 'a person or thing seen as comparable to another.'
Analogue horror is a sub-genre of horror which plays with both of these concepts. It uses the 1950s, VHS-like imagery of videos like emergency broadcasts, propaganda, archival footage, or PSAs to appear familiar whilst adding supernatural and unfamiliar aspects which unsettle a viewer. The techniques are used in video games like 'Discover My Body' 'Assessment Examination' and 'Maple County' but are used in videos also.
This is particularly noticeable in the Mandela Catalogues, a YouTube series created by Alex Kister about doppelgangers called alternates who seek out their human version and kill them to take their place. There is a deeper mystery but the stand-out feature is the feeling of dread, fear, and unsettling familiarity set from the very beginning:
It is an effective means of storytelling because the technology in relation to the modern era is inherently flawed so the jarring cuts and sound disruptions are fitting for the format. Also, the type of video they are emulating is designed to remain in your subconscious by being concise and simple due to the (usually) life-saving knowledge they contain so, by twisting them to scare a viewer, it invokes a far more primal fear because you don't know who to trust.
Another example of this is Local58, which has multiple videos which appear to be being hijacked in an attempt to get people to act against their best interests:
Weather service is especially effective to me. The constant pushing and pulling and the innate feeling that something as normal as the moon is betraying you is very effective. Then, the final shot of the VHS camera being pointed to the moon is genuinely hard to watch because of the implications forced into your mind by the emergency broadcast which preceded it.
A more light-hearted example, not in the horror genre but which I still consider in the analogue subgenre, is OmegaMart, which aims not to scare its viewers but to create abnormal and otherworldly concepts in something as normal as a supermarket advert. Their products and location genuinely exist to visit.