This video explains how to achieve an American English accent by focusing on mouth posture and the "center of gravity" for sounds, rather than traditional "voice placement" or simply relaxing. The host, Josh, argues that American English utilizes a specific mouth and tongue positioning, particularly around the schwa sound, which influences all other sounds. He breaks down four key areas to focus on: jaw, tongue, throat, and lips, providing practical advice and exercises to help viewers adjust their pronunciation.