It is not subtle. Real estate agents insult, yell and demean property owners. It is a tactic they use to intimidate and manipulate, even break a property owner.
Once the agent has lied, threatened and intimidated the property owner, it is easier for them to get them to agree to arrangements that might not be in their best interest. Agents have been reported to use gossip and slander from neighbors as a way of berating the home seller, and gaining a psychological advantage. Agents will even use threats of violence and the suggestion that they can be put out of their homes.
If you are abused, threatened, bullied or harmed in any way by a real estate agent - contact the authorities, get a lawyer,, and report them to the boards of real estate in their state.