It is most likely an invitation to play. The bow is a classic appeal for play between dogs. The whining and high pitched bark can be for the same reason. Because she cannot just run over, she is trying to get the other dog to her.
She wants to play. It's called a "dog bow", which is an invitation to play. Practically normal. Dogs bark to try to get attention from the other dogs..kinda like "Hey, you want to play?"