Star Trek: Alternate Reality Uniforms Ranked Worst To Best
9. Mirror Universe (22nd Century)
The Terran Empire variations of the Enterprise-era jumpsuits are fairly close to their Prime Universe counterparts. This is most evident in the male characters, as the female characters were given the standard 'evil lady' trim, meaning they were given less material, so that more skin could appear.
The real focus for In A Mirror, Darkly was the updated TOS uniforms bearing the new Defiant delta. When TOS was on the air, each individual ship and starbase had their own delta, with the now-standard one hailing from the Enterprise. However, Bob Justman put a stop to this (per Roddenberry's instructions) before the third season, so the Defiant originally had no unique delta.
For In A Mirror, Darkly, a special Delta was created for the ship, first seen on the chest of a slain Redshirt, then on the Enterprise crew after they've commandeered the vessel. In truth, this entry combines both the 22nd and 23rd century, though they make a great pairing, truth be told.