Revealed: the major clue to THAT Star Trek Discovery twist every fan missed, even you
It was hiding in plain sight ***spoilers dead ahead***
The clues were all there. Lorca's un-Starfleet behaviour. His obsession with Burnham. Plus, the funky business with the clone Stamets in the mirror. Yet the reveal that not only was the Mirror Universe going to play a big role in Discovery, but that Lorca was actually from there still managed to shock, even if some fans had worked it out ahead of time.
One thing we can almost guarantee you didn't notice? This.
Yes, as TrekCore points out, the poster for Discovery looks an awful lot like the insignia for the Terran Empire – the Mirror Universe's devious counterpart to Starfleet. Usually we would dismiss something like this as a coincidence, but the composition is almost exactly the same: a planet, delta sign behind it, the Discovery's warp trail matches the dagger, Burnham's eye even stands in for the knife's pommel!
We're pretty convinced this was deliberate, although can't say for sure whether the poster or the insignia came first. Now, if only someone could find a poster that would explain why there's so much sex and gore in a Star Trek show...