Gorgeous pictures.
Does she know she is not part of the pack, no other idea.

i would go along with that ........my Sophie always waits till last and sits a little behind the others she is spayed so dropped to bottom in a pack of entire bitches ...

I think you could be right. The only thing what made me think otherwise is they dont do it between themselfs(i would have thought the stronger dog would) and Junior(other nextdoor dog) doesnt hes always at the front of the que, despite being more submissive than Coco.

Fantastic photos. Maybe it's because if she sits at the back looking cute and lonely you might throw her more treats.

Heidi