Final answer:
Cindy Sherman's Untitled Film Stills series was influenced by the Postmodern art movement, reflecting on the stereotypes of women in media and challenging conventions.
Step-by-step explanation:
The movement that influenced Cindy Sherman's Untitled Film Stills series is the Postmodern art movement. Sherman's work is a critique of the stereotypical portrayal of women in media and films. Her series, which consists of black and white photographs resembling film stills from 1950s and 60s Hollywood, European arthouse films, and B movies, explores themes of identity and gender representation. The Postmodern movement, which gained prominence in the mid-to-late 20th century, is characterized by its questioning of authority, breaking of conventions, and mixing of styles and ideas from different time periods and cultures. Sherman's work also reflects on the influence of media in constructing femininity and identity.