When Star Trek: Discovery went to the “evil” Mirror Universe in its first season, it was a blast from the past — a concept first created for The Original Series when Spock got a goatee! And while this year’s Disco panel at San Diego Comic-Con was very much about looking forward to Season 2, including Captain Pike’s arrival on the USS Enterprise and a mystery surrounding Michael Burnham’s brother Spock, CBS All Access also had a great exhibit on site featuring many of the costumes, props and concept art that brought the Mirror Universe to life in Season 1.
Source: IGN.com Get Up Close and Personal with Star Trek's Mirror Universe Props and Costumes