Although it was broadcast as part of the fourth season, this episode was produced during Season Three. This is evidenced by the fact that a clip from this episode was shown in the third season finale A Special Edition (1997).
The term "quantum mirror" was also used to refer to a device used to travel to parallel universes in There But for the Grace of God (1998), which was broadcast only four days after this episode. Brad Wright, the series' co-executive producer and the co-writer of this episode, is the co-creator of Stargate SG-1 (1997). Furthermore, both The Outer Limits (1995) and Stargate SG-1 (1997) aired on Showtime at this time.