Censorship

Nikolai Yezhov, standing to the right of Joseph Stalin, was shot in 1940. He was edited out of the photo by Soviet censors after his execution as a form of damnatio memoriae.

Wikipedia - "Censorship is suppression of speech or other communication which may be considered objectionable, harmful, sensitive, or inconvenient to the general body of people as determined by a government, media outlet, or other controlling body."
Wikipedia