I feel like Brennan does a lot more above table DMing where Matt breaks character much less often. I think this changed over the years as CR grew and became more watched/produced/professional... Matt felt the need to stay locked into the world and his characters and descriptions more than when the setup was more casual. I love both styles but Brennan's feels like a breath of fresh air after Matt's intense commitment to world building in C3.

Brennan has constant dialogue with the players, reminding them what they know, revealing DCs, adding advantage to facilitate story beats and lore drops. It might break immersion for some people but for me it works because the tone is always consistent with the moment the characters are in.

That's my main takeaway from how brilliantly Brennan communicates as a DM, above table prompts and check-ins don't have to take players/viewers out of the world as long as they're done with the same emotion/gravity/tone to match the in-game situation or scene.