Just wanted to update this in case anyone comes in the future looking for a review. TL;DR, I am very pleased with the value of our session.
I was initially frustrated following the prep session. I wanted to do a full mock interview and then review that mock interview; however, Sandy thought that there was quite a bit of opportunity to improve my initial response to the very first question. For the next 20-30 minutes, we really dove in on this question and he asked me again and again. I was feeling pretty down tbh since I had come into our session feeling prepared. Sandy was encouraging though, stating that it is just important to get this right as it sets the tone - and direction - of the interview.
The rest of the session was great - we exhausted the hour pretty quickly but Sandy was nice enough to pretend not to notice. I believe our session was maybe 90-100 minutes long by the end.
Sandy was right to focus in on that first question - as that was my first question during my interview. Being able to explain what I do in a straight-forward manner to the interviewers really enabled me to feel confident on the next few questions and finish out the interview strong.
Good luck to ya if you are reading this post - I'm sure you will do great on whatever path to wherever you are headed!