If a friend offered to email you pictures of him/herself, and when you saw the pictures, they didn't match up with photos you'd already seen of that person on AB, what would you think?

That would be pretty weird. Shapeshifters are scary things.

I would think that the person felt he/she had a reason for being untruthful. It may not be motivated by deceit, but by fear of rejection or shyness.

some people may change a lot, but, I tend to be a little leary (I grew up in Missouri..the "Show Me" state, after all). I would be suspicious. If it were me, I'd think the person was lying or had something to hide.

I'd wonder how good of a friend this person was. If it's anyone who's going to be at the L.A. convention, you should probably notify the organizers.

I'd think something fishy was going on and be very skeptical about that person from that moment on.

be afraid be very afraid. they are pulling a fly one on you. steer clear.

Initially, I'd try to give them the benefit of the doubt and not immediately segue into suspicion or aggression or assume that they had intentionally tried to falsify their appearance. Starting from that stance, I'd just take the direct route and ask them about it. That way, no matter how the inconsistency occurred, be it an intentional deception on their part, or just an innocent mistake or misunderstanding, we could at least avoid a nasty argument over it.

Now, this is why I wanna remain faceless here. I don't like disappointing people. =)

It depends how different they were. Stableboy told me once if he lined up every photo he's seen of me he feels like he's looking at 5 different girls...and they were all from the same time period. So I think I'd allow for some differences, but obviously if s/he was blatantly a different person I'd ask them why they were posting fake pictures on the internet. Depending on what they said, I might warn others.