The "in breakfast there are chickens and there are pigs" analogy is a popular one in Agile circles. It refers to the idea that in a given project there are people who are fully committed (pigs, developers) and people those who are merely invested (chickens, stakeholders). I take issue with this idea. I reject it.
My main beef (not to mix food items) here centers on the notion that there are two levels or classes of involvement. This idea practically opens the door for a lack of accountability and the empty suit anti-pattern.
Managers in an Agile process have to manage. They must remove blocks on the development team's productivity by ruthlessly chasing out waste, navigating political waters, begging/borrowing/stealing, etc. Agile isn't just TDD/BDD, continuous integration, and pair programming. It's for everyone at all levels and in all roles.
Stakeholders, domain experts, and users are equally accountable for the success of a project. They need to author stories, prioritize them, and drive ongoing analysis and clarity. Yes you can proxy these roles to a product owner, sure, but a good product owner will exhibit accountability by streamlining communication over acting unilaterally. Stakeholders must make the commitment to be available. They are invested: ownership.
I can hear the counter argument to this post now: "but doesn't chickens and pigs refer to the daily stand up." Yes, the stand-up should be open to anyone with skin in the game and only developers should provide updates in this context, but to say that everyone in the room isn't fully invested is a plaintive mistruth. Going even deeper, chicken/pig applied only to the stand up invests in the stand up a kind of all importance that leads us to place an undue amount of general purpose importance on this single practice. That's a distraction; stand ups are an important process, but they're just one component of a culture of constant improvement.
You are a pig. Your boss is a pig. Your CIO? A pig. If people aren't clear on their status as slabs of bacon, you've got yourself another impediment for your list, a big one.