WARNING: Contains SPOILERS for Star Trek: Prodigy, season 2, episode 14, “Cracked Mirror”.
Summary
While it may seem thatStar Trek: Prodigy’s Mirror Universe episode contradictsStar Trek: Deep SpaceNine, the truth is more complicated. InStar Trek: Prodigyseason 2, episode 14, “Cracked Mirror”, written by Erin McNamara, and directed by Ruolin Li, a 24th century Starfleet crew interacts with the Mirror Universe for the first time sinceDS9season 7. “Cracked Mirror” introduces theMirror Universe versions ofStar Trek: Voyagercharacters, Admiral Janeway (Kate Mulgrew) and Captain Chakotay (Robert Beltran), who are high-ranking figures in the New Terran Armada, which appears to contradict the history established byDS9’s Mirror Universe episodes.
Star Trek: Deep Space Nineseason 2, episode 23, “Crossover” revealed that Captain James T. Kirk (William Shatner) inadvertently brought down the Terran Empire by inspiring theMirror Universe’s Spock(Leonard Nimoy) to push for more benevolent reform. This weakened the Terran Empire, and left them open to attack from the Klingon-Cardassian Alliance, leading to the empire being devolved, and the enslavement of the Terrans.DS9’s Mirror Universe episodes depicted a burgeoning Terran rebellion against the Klingon-Cardassian Alliance, paving the way forStar Trek: Prodigy’s “Cracked Mirror”.

Worf Ruled The Mirror Universe In Star Trek: Deep Space Nine (No, Really)
Worf is the only TNG character to appear in Star Trek’s Mirror Universe, and Deep Space Nine revealed that he was the Regent and supreme ruler!
Does Star Trek: Prodigy Contradict DS9’s Mirror Universe Arc?
Captain Chakotay and the USS Protostar crew find themselves aboard the ISS Voyager-A inStar Trek: Prodigyseason 2, episode 14, “Cracked Mirror”. The Mirror Universe’s Janeway and Chakotay are dressed in very similar Terran uniforms to those first seen inStar Trek: The Original Series. The ISS Voyager-A also has its own Agonizer, and Admiral Janeway specifically mentions the New Terran Armada. All of this suggests that, in some form,the Terran Empire is back up and running in the Mirror Universe’s late 24th century.
There was never any suggestion inDS9that the Terrans had huge warships like the ISS Voyager-A.

This appears to contradictStar Trek: Deep Space Nine’s Mirror Universe arc, because a few years earlier, the Terrans were slaves and freedom fighters. The Terran Rebellion encountered by Commander Benjamin Sisko (Avery Brooks) inDS9season 3, episode 19, “Through the Looking Glass” were a passionate, but scrappy, band of rebels. There was never any suggestion inDS9that the Terrans had huge warships like the ISS Voyager-A. However, Sisko’s impact on the Mirror Universe inDS9may have paved the way for the New Terran Armada to become a viable force in the late 24th century.
Why Star Trek: Prodigy’s Mirror Universe Episode Isn’t A Plothole
While the Terran Rebellion may not have had a huge warship like the ISS Voyager-A inStar Trek: Deep Space Nine, the Mirror Universe did have an ISS Defiant, courtesy of Captain Sisko. The Mirror Universe’s Defiant enabled the Terrans to fight back against the Klingon-Cardassian Alliance, so that technology could be used to build new warships. In an interview withStar Trek: Prodigy’s co-executive producer Aaron J Waltke, the writer and producer explainedwhat happened to the Mirror Universe afterDS9.Read Aaron J. Waltke’s quote below:
So in my mind, it seems unlikely that they would all just be good guys now. Especially because them making major reforms to their society with Mirror Spock ultimately, as stated in DS9, is what allowed their society to collapse and become vulnerable to the other outside forces. So we thought at least some faction would probably be like, ‘We have to go back to the old ways’. And that’s how we get the classic sleeveless shirts and the knives they have attached to their little holsters.

Rather than contradictStar Trek: Deep Space Nine,Star Trek: Prodigy’s Mirror Universe episode builds on the history it established. Given how the Terran Empire was broken down and enslaved, it stands to reason that the society would harden in their attempts to prevent history from repeating itself. Therefore, the New Terran Armada are a more heavily tooled up version ofStar Trek: Deep Space Nine’s Terran rebels, setting out in pursuit of the galactic conquest pursued by their ancestors.
All episodes ofStar Trek: Prodigyseason 2 are streaming now on Netflix.

Star Trek: Deep Space Nine
Cast
Star Trek: Deep Space Nine, also known as DS9, is the fourth series in the long-running Sci-Fi franchise, Star Trek. DS9 was created by Rick Berman and Michael Piller, and stars Avery Brooks, René Auberjonois, Terry Farrell, and Cirroc Lofton. This particular series follows a group of individuals in a space station near a planet called Bajor.
Star Trek: Prodigy
Star Trek: Prodigy is the first TV series in the Star Trek franchise marketed toward children, and one of the few animated series in the franchise. The story follows a group of young aliens who find a stolen Starfleet ship and use it to escape from the Tars Lamora prison colony where they are all held captive. Working together with the help of a holographic Captain Kathryn Janeway (Kate Mulgrew), the new crew of the USS Protostar must find their way back to the Alpha Quadrant to warn the Federation of the deadly threat that is pursuing them.