From the Saatchi Gallery description of the piece:

The act of the film’s being remembered – the emotional and intellectual associations within the artist’s mind – is Clements’ real subject. Travels with Myra Hudson, for example, takes Joan Crawford’s 1952 film Sudden Fear as its subject, in which Crawford plays the character of the drawing’s title. Travelling from left to right, Clements’ drawing parallels both the literal journey that drives the film forward – from Hudson’s book-lined study, down a sudden staircase, into the compartment of a zooming train – and the movement of Clements’ own recollections of the film, where certain details gain stronger purchase in the memory than others.