"Those in power are fascinated, and bystanders comment." .
Bureau: chess game; Trial: clear and cautious
Chess players are often confused, but they know this situation very well.
Later, it developed into "the authorities are fascinated, and the onlookers are clear."
Moreover, the meaning is extended, that is to say, when you are in one thing, you are often confused because you think too much about gains and losses, while the onlookers see it clearly because they are calm and objective.
Now there is also a saying that "the interested parties are lost, and the onlookers are clear", which is probably the extension.