Coaching from the A-Line

Hi! I am in the middle of listening to Brooke’s latest podcast episode (not the private podcast) and her guest mentioned the idea of coaching from the A-line, but neither of them clarified. What does that mean? I vaguely remember hearing that mentioned before I started in SCS a few months ago, but I don’t see in in the Terms/Concepts video…. Can you please explain that? Thanks so much!!!