In a Mirror, Darkly-I disagree a bit here. I thought it was inspired to have the TOS Defiant, lost in the TOS Episode "Tholian Web" reappear in this timeframe. I thought it was insinuated that this was how the Empire came to look as it did in Mirror, Mirror. Becuase the Empire spent a century or so reverse engineering the Defiant instead of making their own technological strives.
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