You may take the exact same shot multiple times, but varying the angle and degree of lighting on the subject can create a drastically different mood for each shot.
How to Use Fill Light in Photography
Dynamic High-Key And Low-Key Portrait Lighting Tutorial
Key Light Photography: A Beginner's Guide
How to Photograph an Editorial Headshot Using Butterfly Lighting
Getting Started with One-Light Low-Key Portraits
How To Use iPhone Portrait Mode To Shoot Stunning Portrait Photos
How to Use Fill Light in Photography
How to Shoot an Amazing HIGH KEY Portrait with just ONE Sony Speedlight
How To Use iPhone Portrait Mode To Shoot Stunning Portrait Photos