Mallory, "You have to put your self in the shoes of the japanese; to them, bowing is the equivilent of a hand shake" - not quite true, social/business status etc. can all be conferred by depth of bow. If it really is just a handshake, there wouldn't have been a major discussion over how low lift operators should bow to their "guests". Perhaps this is changing, but I think most of the time when bowing non-japanese are using their free "gaijin" pass so the intent is acknowledged and their lack of understanding of the subtleties is politely ignored.
As for bowing to a picture, never understood this one and never have done it. I can cope with bowing to a person, but a picture does get my goat.