Okay so we've seen almost every character look into a mirror a little longer than usual this season in the flashsidways.
My theory is that the producers have been hiding something in the flashsideways. I bet you that when the characters are looking into the mirrors longer, they are actually seeing flashes of the Island like Desmond with Charlie. But the producers never showed us it yet.
I think in the next episode we will see them all looking into the mirror and seeing something.
I also think only prominent features stand out if the characters can see them in the mirror. Like love, or a catastrophe (like a bomb (Faraday)).
Thought: Since Desmond was knocked out for 3 days, what was Sayid doing? Did he go back to Locke or stay at Hydra? What do you guys think?