This is something I haven't had to deal with. And my children had no problem with it either. Let me think if I can explain the opposite experience of this - very secure object constancy.

I can say neither I nor my kids every needed transitional objects, photos, etc. to maintain that secure assurance and trust in the adults (or others) in our lives. It is that complete faith that the other person hasn't emotionally gone anywhere when they physically aren't there. Their caring and that relationship still exists even in absence.

I can remember my kids being completely comfortable going to daycare and school. They were like "bye Mom" (if they even bothered to say "bye Mom" before they ran off to play). Even on extended vacations, etc., they were perfectly comfortable with their aunts or cousins or grandparents while we were away. I guess it was an innate trust and deep sense of safety.

My husband didn't have that kind of upbringing. His childhood was anything but safe; his family was not safe. It took him many years into our marriage before he was comfortable with me being away for extended periods of time (such as to visit family or something like that). As our relationship has matured and he has come into our own little family with our own kids, his anxiety about me being away has improved greatly. I think it took him establishing his own safe family and putting down his own "roots" where he was able to grow away from those bad early experiences for him to find his own place of constancy in our own family and relationships. He had to basically "end" his old family ties and "begin" his own new family where he was in control.