It's mean to make fun of deaf people.
Ian is walking through a convention center when he sees a room full of deaf people signing to each other.
Ian wants to observe the deaf people.
Ian sees all of the crazy hand motions and picks up a flyer to learn more about what they are doing.
Ian sees all of the crazy hand motions and starts laughing uncontrollably, pointing at them.
A deaf person comes up and interacts with Ian, and Ian learns more about deaf people.
Some large deaf people get very angry and escort Ian away from the room.