There's a moment in Suicide Squad where the filmmakers recreate this iconic comic book cover.
The cover was an homage to the Harley Quinn which had appeared in the Batman: The Animated Series television show, which is where Harley was first seen and developed. That series made Harley so famous, she moved over into the comic books. The comics quickly jettisoned her Harlequin outfit in favor of a "slutty baby doll" look with pigtails. But occasionally, DC Comics would remind us of Harley's origins... as with covers like this.