It is possible to argue of course that most communication is in some way persuasive. Michel Foucault refers to this as the 'position of annunciation', or the place from which we speak. The claim of 'biased' speech almost always comes from a response that is at odds with the first speaker. That is, biased speech is the speech of the 'other'. Overt examples of persuasive visual communication include advertisements and political propaganda.
Persuasive communication aims at both convincing and producing desire in the viewer, or receiver.
However, not all listeners or viewers receive a message in the same way. In addition to the overt message propaganda includes more subtle messages. That is, propaganda may carry several messages on different levels of signification. Messages may also be received on a subconscious level. In the 1970s subliminal advertising, in which words and images of a sexual nature were flashed momentarily on the television screen, raised public concern around some of the ethical issues related to advertising.