Background art plays a crucial role in setting the tone and atmosphere of a series. It helps establish the setting, whether it be a futuristic city, a magical forest, or a post-apocalyptic world, which in turn immerses the viewers into the story. The colors, details, and design of the background art can evoke certain emotions and enhance the overall mood of the series, making it more engaging and believable for the audience. Good background art can truly bring a fictional world to life and enhance the viewer's experience.