That's a good one.  The serious or disturbed dog look is a funny one.  Nadi will sometimes get a concerned look on her face when we are somewhere new or if she is on a stool in a restaurant and I get too far away from her.  I like that she is so attached to me but sometimes I think she might be a little too attached.   I have very infrequently left her behind in her life but those must have been pretty traumatizing because now every time I go just a little bit out of her sight, she has a bit of a panic attack.