When you're Emperor, you get to wear what you want, so why wouldn't Georgiou opt for something like this?
At San Diego Comic-Con 2018, we got an early look at many of the costumes worn by the Mirror Universe versions of the Star Trek: Discovery's cast, the design for which was spearheaded by costume designer Gersha Phillips. (Disclosure: Star Trek: Discovery airs on CBS All Access; CBS is CNET's parent company.)
You can't have an Empire without the equipment to rule it. From the top in reverse-clockwise order, there's a Phaser Rifle, a Hand Phaser, a pair of standard-issue daggers and a hand agonizer. It's pretty safe to say you're the bad guys if you're walking around with daggers and agonizers.
Fine. If you've had enough of Georgiou's golden Emperor robes, here's her uniform as she was working undercover on the Klingon homeworld. The costume designer Gersha Phillips aimed for a "space pirate" look for this particular outfit.