just thinking ................................................
each episode so far this season has featured a moment where a character looks views themselves in a mirror... jack the cut on his neck in the plane kate in the autoshop locke in the shaving mirror now jack again in the mirror with his appendix scar.
and in this past episode we got a direct reference to lewis carrol's 'through the looking glass.'
i think it's fair to assume then that the flashsideways world is showing us our regular losties 'though the looking glass" i.e. the mirror image of themselves.
from the wikipedia summary of 'through the looking glass' "Although it makes no reference to the events in the earlier book, the themes and settings of Through the Looking-Glass make it a kind of mirror image of Wonderland: the first book begins outdoors, in the warm month of May, uses frequent changes in size as a plot device, and draws on the imagery of playing cards; the second opens indoors on a snowy, wintry night exactly six months later, uses frequent changes in time and spatial directions as a plot device, and draws on the imagery of chess. In it, there are many mirror themes, including opposites, time running backwards, and so on."
we're getting themes and settings from our original timeline without the characters knowinging referencing it (obviously. they have no knowledge of it.) and in many cases, we see characters with mirrored characteristics of the original timeline...hurley's bad luck/ good luck. locke's bad dad/good dad relationship. jack's father issues/son issues. it's as if they've gone through the same basic experiences but the resulting effect on their personality and life is the mirror opposite of what we saw in the original timeline.
i know this is nothing really groundbreaking. it's just nice to see things fit together nicely! go writers!