So what does Roger do? He takes the lead.
Roger was already “noodling” with the idea of approaching Jim Hobart, I think. That’s why he was so happy in the previous episode, when he understood that Bob Benson was going to Buick. Roger likes knowing how to negotiate and what the game is. Roger is often lackluster at work; he’s a great account man who doesn’t always bother. From Season 1, he’s felt “my name on the building” gave him all sorts of special privileges, and that included being pretty lazy when he felt like it.
But two things happen after Bert dies. Bert, the father figure. Bert, the man who has looked after Roger ever since the senior Sterling died. Bert, whom Roger hears say “You’re not a leader”. First, Roger tells Jim Hobart that he must be president of SC&P after acquisition. Second, he takes control of a partners meeting that was on the edge of devolving into argument and acrimony. Sit, have coffee, and listen.
Roger was never more aware of needing to impress Bert Cooper than in that moment, when Bert was gone.