[post_page_title]Always polite[/post_page_title]
Even if a guest is quickly escorted out because the Queen is not enjoying the conversation, it will still be done politely. After all, these are the Royals we’re talking about.
A member of the staff might come up to said person and tell them that someone else is waiting for their audience, or come up with another clever way to delicately end the conversation. This avoids leaving people with an unpleasant feeling after their meeting with the Queen.