loch henry

hi! i’ve just started watching black mirror and i’m watching random episodes not in order. i’ve just finished loch henry and loved it so much, but i don’t understand how it’s tied to black mirror? i though the series was about a dystopian future, or anyway bad things that can happen due to elevated technology, but how’s this episode related to that? i found it very normal and likely to happen or even happen in the 90s since it only has the tapes as a technologic element