[Discussion] My puppy sits on the ground, and leans her head way back, which exposes her neck, when she meets a very excited dog. Why is that?

She is 4 months old, and is a bit timid right now around other dogs, but doesn't ever get aggressive, just shy. This has happened on several occasions, when a dog is very excited to meet her and jumping around and sniffing her like crazy. She just sits there, and puts the back of her head almost to her back, completely exposing herself. I assume this is to show she is not a threat and is being submissive, but I have never seen a dog do this, and couldn't find anything about it when I google searched it. via /r/dogs http://ift.tt/2sKDxK2