Covert intimidation conveys a threat without ever making an overt one — a look, a tone shift, a veiled comment — leaving the target uneasy but unable to point to anything concrete they could describe to someone else. George Simon identifies this as especially effective against conflict-averse people, since it exploits exactly the instinct that would otherwise defuse a direct confrontation: staying calm and non-confrontational offers no protection against a threat that was never voiced in the first place.
The manipulator gets the compliance-inducing effect of intimidation while maintaining full deniability — if challenged, there's nothing specific to challenge. Simon's guidance is to name the felt effect rather than trying to prove intent: "I notice I feel uneasy after that exchange" is a legitimate data point even when there's no single sentence to quote back.