Shills simulate anons with a tactic called Kayfabe
The term comes from wrestling.
While the scripted nature of professional wrestling was an open secret it was not generally acknowledged by people in the business. Often wrestlers and promoters would make sure that on-screen rivals were not seen eating or traveling together between shows and so on. There were a few occasional 'hiccups' at the time, such as an infamous incident in 1987 in which police arrested The Iron Sheik and Hacksaw Jim Duggan, supposed rivals in an upcoming match at Madison Square Garden, as they sat together in a car drinking and using cocaine. The first public acknowledgment by a major insider of the staged nature of professional wrestling came in 1989, when World Wrestling Federation owner Vince McMahon testified before the New Jersey State Senate that wrestling was not a competitive sport. The admission on McMahon's part was to avoid interference from state athletic commissions and to avoid paying the taxation some states placed on income from athletic events held in that state, as well as to avoid the need to meet the requirement of having to employ medical professionals standing by, as was generally mandatory for legitimate contact sports involving substantial possibility of injury.[6]
https://en.wikipedia.org/wiki/Kayfabe