The figure 's mouth is opened wide as if screaming , an expression Bacon took from a still he kept of the nurse screaming in Sergei Eisenstein 's Odessa Steps massacre sequence in his 1925 silent film Battleship Potemkin . In 1984 , the broadcaster Melvyn Bragg asked Bacon about the still , and observed that in his earlier career the artist seemed preoccupied with the physicality of the human mouth . Bacon replied , " I had always thought that I would be able to make the mouth with all the beauty of a Monet landscape though I never succeeded in doing so . " When Bragg asked why he thought he had failed , Bacon said , " It should be all much more colour , should have got more of the interior of the mouth , with all the colours of the interior of the mouth , but I didn 't happen to get it . " His interest in the mouth was further stimulated by a medical textbook of diseased oral cavities bought in a second @-@ hand bookshop , kept in his studio and to which he often referred to .