Unfortunately I can't offer a huge amount here from personal experience - I've never actually done a TC interview (dropped out of
NRF and Travers made my offer without asking me to interview again). With that said, my general understanding of these post-VS interviews is that you've really got to place more reliance on things you've learned and done during the VS and how that's changed your position in terms of knowledge/ experience/ desire for a TC compared to before the VS.
With that in mind, you want to keep a really accurate log of everything you've learned/ done etc during your VS, who you've spoken to, what they've said etc etc so you can bring all that into the discussion.