Bells and whistles refers to non-essential features, visual or functional, that are an enhancement to an object.

Bells and Whistles
Bells and Whistles
Bells and Whistles
Mozilla dissected
Face Detection without Bells and Whistles
Face Detection without Bells and Whistles
Face Detection without Bells and Whistles
Explicating Sensationalism in Television News: Content and the Bells and Whistles of Form
HIV protease inhibitors and nuclear lamin processing: Getting the right bells and whistles
Bell and whistles : more speculative realism
ISSUES IN TECHNOLOGY: THE LURE OF BELLS AND WHISTLES CHOOSING THE BEST SOFTWARE TO SUPPORT READING INSTRUCTION
Teaching with Multimedia: Do Bells and Whistles Help Students Learn?
Discriminative Invariant Kernel Features: A Bells-and-Whistles-Free Approach to Unsupervised Face Recognition and Pose Estimation