I just had one a half hour ago. It’s literally just a discussion about your development as a partner. She chatted about how I have improved as a partner, made sure I understood bean stock, Fidelity, and other partner benefits, asked me if I understood a couple key things like the LATTE and APRON models (just simple things to keep in mind while interacting w partners and customers, I’m sure your SM will review) and then we chatted about some of my goals both personal and Starbucks related (do I want to be a barista trainer? A shift?) and what we can do to meet those goals. It’s an easy half-hour conversation about you. Not a bad thing! Just a check-in! Don’t forget to clock that time and enjoy your free partner beverage!

tl;dr it's a check-up to see how you're doing, make sure you're up to date on info you're supposed to get like benefits, a chance to talk over any issues you might have or future changes like scheduling.