"If you believe the decision is THEIRS then you’re doing it wrong"?

In a recent coaching call, Brooke was coaching a woman who was being trained for a promotion and dealing with her own self-doubt that she would get the job when it was time for the board of directors to hire someone.
I completely understand all of the coaching that Brooke offered about how she can choose to see herself, and that there is no upside to believing she won’t get the job, and no downside to believing that she will get the job.
The part that confused me was when Brooke said: “You are in control of whether you get the job or not. If you believe the decision is THEIRS whether you get the job or not, you’re doing it wrong.”
I do understand that we create our own results, and I can see how the woman will show up differently in the process if she believes she can get the job. But what I don’t understand is that factually it seems like the final decision IS theirs (the board of directors). That even if she shows up perfectly for what they are looking for, they could choose to hire their own family member or some other unforeseen circumstance. The final decision part of the result seems to be outside of her control (and therefore a neutral circumstance) because it involves other people’s models and actions, not something she can decide and control.
Can you help me to understand what Brooke means and to believe that the decision of if she will get the job is HERS and not THEIRS?