Diagonal dark lines on a black background.  Diagonal streaks.

Diagonal streaks on black background.

The image shows a blurred, diagonal effect, likely created by a fast-moving light source against a dark background. There are no people or objects discernible. The "what" is a motion blur effect, and the "why" is likely a photographic technique to capture movement or a specific artistic effect.

Photo size: 160.0 Mpixels (458 MB uncompressed) - 16000x10000 pixels (53.3x33.3 in / 135.5x84.7 cm at 300 ppi)