If your interest is in the science rather than just the visuals, these resources explain the "why" and "how" of post-mortem changes:

This article explores the growing trend of consuming postmortem and forensic content, the platforms hosting this material, the ethical considerations, and the impact on viewer psychology. 1. The Rise of Forensic Entertainment

Humans have a natural curiosity about death, which this content feeds. It is a form of voyeurism that is now easily accessible, providing a safe way to explore the "forbidden" topic of human remains. 5. Conclusion