Not sure what I am missing. But all the possible moves lead to dead states.
That being said, not sure what the transition labels mean. "Somebody at bone", "Somebody at carrot" or "nobody at bone" means nothing to me. I suspect there's another game that I don't know about that would provide the context.
The path with that label is blocked unless the condition is fulfilled. I don't think it relies on any prior knowledge (at least nothing specific I can think of)
It's entirely self-contained. "Bone" is a node in the graph, put either a bunny or dog on the bone and that "somebody at bone" path will be enabled because its condition will be enabled.
That being said, not sure what the transition labels mean. "Somebody at bone", "Somebody at carrot" or "nobody at bone" means nothing to me. I suspect there's another game that I don't know about that would provide the context.