Hall's theory:
This poster of the film Ted shows preferred and oppositional readings. It shows preferred readings as the operator wants the audience to view the media text that it is going to be quite rude because it is a picture of a teddy bear that is alive and drinking alcohol, sitting on the sofa. So what you see in this image is what you think is going to happen in the film. This poster also shows oppositional readings because some people might look at this image and see a sweet, innocent, little teddy bear that is a child's play toy and that's what they assume the film is going to be about. But in fact it is the total opposite.