Final panel next week: how do you “talk” design without sounding like a robot?

I have got a junior GD final at a tech company next week. 2-hour panel (CD + PM + someone from marketing? I think). I’m okay showing files (Figma + a couple of Illustrator pieces) but I always trip over the talking part: connecting moodboards → constraints → trade-offs.

I have a non-traditional background (psychology → in-house → freelance at an agency). I currently spend most of my time on presentations and brand-related layout work, so I'm trying to cultivate "design thinking."

I've been practicing with friends on Zoom, answering questions under timed conditions. I've also tried using the Beyz interview helper for mock interviews, practicing behavioral interviewing techniques (stakeholder conflict, feedback loops, "Please give an example..."). This helps me stay concise, but I still feel awkward when asked, "Please give a complete description of a project." If you've ever been an interviewer, what do you expect junior interviewers to do in an interview?

Also, how many metrics should I discuss to avoid falsifying ROI? Are there any common structures or tips that can help? I'm compiling some simple phrases. Any sincere and practical advice would be greatly appreciated.