Ok, I think I figured out some of it. Firefox has a Facebook Container that apparently was preventing images linked to through Facebook from showing up. I'm not sure if all the ones I couldn't see were because of that, but I guess I'll see if that fixed all of it.
I'm using Firefox and images just show as [IMG] I've tried clearing cookies/cache and making sure Firefox or add-ons aren't blocking any content, but it's still not showing up.