It is an analogy and the essential point is that each step leads to the next, just like, in case of dominoes (when they work), each one topples the next.
You have focused upon a case where the analogy breaks. It is a good idea to detect such cases and maybe it makes the analogy less useful for you, if the parts where the analogy does not work are, for you, essential features of the phenomenon. This is okay.
Hopefully you have mastered the concept while thinking through the matter; if so, the analogy has served its need, and if not, you should solve some problems and build more intuition.