Here's somemore about the mirror scenes I just mentioned:
LA X - Jack looks into the plane's lavatory mirror, noticing a wound on his neck. [alt]
What Kate Does - Upon arriving at the garage, Kate catches a glimpse of herself in the mirror before leaving to give Claire a ride. [alt]
The Substitute - After John wakes up and gets dressed, he sits at the bathroom sink in front of a small mirror before deciding to try and call Dr. Jack Shephard. [alt]
Lighthouse - Jack gazes at his reflection in the pond near the Temple entrance. Hurley sees himself in the lighthouse mirror. Jack sees his own reflection as the mirrors in the lighthouse move. Jack sees his childhood home in the lighthouse mirror, then smashes it. [org]. Jack notices an appendectomy scar in the mirror before calling his mother to ask how he got it. Jack notices a strip of photos attached to a mirror in his son's room. [alt]
Sundown - One half of Sayid's face is reflected in the door to Nadia's home before she greets him for the first time. [alt]
Dr Linus - Ben sees his reflection in the door of the microwave when cooking dinner for his father. [alt]
Recon - Following an argument with his partner Miles, James looks into a mirror before smashing it in the police station locker room. [alt]
The Package - Sun looks in a mirror and pauses, although there is a repeating knock on the door. Jin's reflection is shown while being held prisoner at the restaurant, although he himself does not see it. [alt]
Happily Ever After - Desmond sees himself in the airport flight screens before encountering Hurley, Claire, George, and Widmore. Desmond's reflection is shown outside of the police station before he meets Charlie. #
# Daniel Widmore's reflection is shown in the car window before he meets Desmond. [Alt]. And by the way, Daniel's reflection was dark. Possibly because he is dead?
The Last Recruit - While prepping surgery, Jack sees Locke's reflection as well as his own in the mirror below Locke's face. Locke does not see his own reflection, however, as he is unconscious. [alt]
The Candidate - Jack and Claire look at each other in the mirror of the music box given by their dad. [alt]
What They Died For - Jack examines another cut that has appeared on his neck in the same spot as the cut he had on Flight 815. Ben looks mournfully at his reflection in the school nurse's office after being beaten up by Desmond. [alt]
Definitely something up with these mirrors... A lot of them seem to happen just before the character encounters a character from the island, too.
Some more -
http://lostpedia.wikia.com/wiki/Alt_Timeline_Mirrors
