The 'Domain Expansion' meme stems from the popular anime and manga series Jujutsu Kaisen, where powerful sorcerers and curses create a unique mental landscape to trap and defeat their enemies. Each domain is unique to the user, such as Gojo Satoru's 'Infinite Void' or Sukuna's 'Malevolent Shrine.' Online, the concept has been adapted into a versatile meme format where users 'expand their domain' to humorously highlight their specific interests, hobbies, or overwhelming presence in a situation. It often features characters using signature hand signs, and the text is modified to represent anything from a messy bedroom to a specific niche internet subculture, signifying total control over that environment.