Scent memory is part of an actor’s arsenal. Woolgar evokes her heavy-smoking grandfather to conjure the pervasive wartime stench of cigarettes. She also recognises the “sulphurous smell” that would accompany the trauma of Miss Roach’s bombed-out London home.
In my experience, scent is simply amazing. One whiff can trigger a flood of forgotten memories about people, places, times. If that were purposely optimized and used ... wow. Cicero's "Palaces of Fragrance"?