I think it is a fair assumption that most of us aren’t mind readers, right?  So why do we think we know what someone is going through just by looking at them?  Naturally, we feel like it is pretty easy to figure out what is happening at that moment by someone’s expression or actions.  Maybe or maybe not.  My point is more times than none, we won’t.  But that doesn’t stop us from reacting to them and being quick to come to a conclusion about someone just by looking at them. So if they have a stern, lost, confused, happy, surprised, mad or blank expression and that usually causes a reaction from us, a sondereffect.  So when I see a smile, I smile. If someone looks mad then I smile even bigger.  But if they look lost I may ask if I can help.  All of those reactions are from a single glance or look.  Amazing that we think we would know what they are thinking or going through.  Unless we talk and ask questions, we truly will not know what others are  going through.