Not Every Image Needs a Description

Some images communicate information or function. Others are decorative and should not create unnecessary noise for someone using assistive technology.

Read / Reference

Understanding WCAG 2.2: 1.1.1 Non-text Content

WCAG guidance on providing equivalent alternatives for non-text content, including the exception for pure decoration.
W3C Decorative Images Tutorial

Practical guidance for images that do not add meaningful information to the page.