Trivia / Lost S03E22 & 23 "Through the Looking Glass"

• California Doubling: Averted for the scenes set in Los Angeles which were actually shot on location in the city rather than in Hawaii like the rest of the series.
• Recycled Set: The hospital scenes were filmed on the sets for Grey's Anatomy.
• Throw It In!: Julie Bowen really was pregnant during filming of this episode. The producers decided to write it in rather than try to hide it as they felt it demonstrated that Sarah has moved on with her life unlike Jack who's still clinging to the past.
• What Could Have Been: The reveal that the Others were building a runway on Hydra Island was originally told to Sawyer in "I Do," but the scene was cut.