The Black Museum episode definitively confirms a shared "Black Mirror" universe.
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11 Surprising "Black Mirror" Facts You (Probably) Never Knew

3. The Black Museum episode definitively confirms a shared "Black Mirror" universe.
The Black Museum episode is overflowing with easter eggs from the other episodes. The bloody tablet, bloody bathtub, and leftover lollipop all allude to earlier episodes in the fourth series. There are even some hidden clues that reference episodes from prior seasons. Photo via Netflix