Upon release, "Mirrors" received generally positive reviews from
music critics. Writing for Consequence of Sound, Alex Young highlighted the song as an "essential track" from
Perfectionist, while AllMusic's Jon O'Brien also denoted it as a standout from the album, calling it "pretty stellar".
AltSounds' Jack Stevin opined that the song was "enjoyable", in spite of "uninspiring lyrics". The song achieved high positions on some European charts. On the
Ö3 Austria Top 40, it spent 20 weeks and peaked at number 7; the track was listed fiftieth on Austria's 2011 year-end chart. "Mirrors" reached number 10 on the
Media Control German single chart, and was 2011's 80th most successful single in the country. The song reached its highest peak of number two on the
Polish Airplay Top 20, for the week ending 15 April 2011; in contrast, the song entered the United Kingdom chart at number 101. In Switzerland, "Mirrors" spent one week, peaking at number 52, whereas in Flanders, it didn't manage to enter the main
Ultratop chart and instead entered the secondary
Ultratip, at number 18. In North America, the single attained limited success—it reached number 35 on the
Canadian Hot 100, and peaked at number 3 on the US
Hot Dance Club Songs. ==Music video==