This is the one that was made before you even showed up for the meeting. This is the one that sets the agenda, determines the goal and establishes the frame.
The decision before the decision is the box. It makes you believe you have the freedom to think and successfully recommend ideas whiles it is confining you to the box of the decision made before decision.
When you think outside the box, what you are actually doing is questioning the decision before the decision.
That decision is far more important and much more difficult to change than the decision you actually believe you are about to make.