Every advertisement carries both a message (a meaningful content) as well as a command about how to interpret the message. The command portion of the message "positions the receiver to adopt a particular attitude towards the report." Herein lies the rub, for viewers do not merely decode content, they also react to being positioned. As viewers accumulate experiences of interpreting ads they develop "vocabularies of motive" with which they negotiate the ways that ads address them. (Herskovitz, 1979; Bateson, 1972).
Normally, viewers tend to be unaware of metacommunication because it consists of routine and unproblematic coding instructions and commands. But in recent years -- in part, because it has become so difficult to differentiate one ad from another -- more and more advertisers have chosen strategies which call attention to the usual underlying metacommunication in their ads. This not only tends to differentiate them from the pack, it also positions them on the side of the viewer with respect to the kinds of assumptions that ads routinely ask us to make. Remember Judith Williamson's observation that in advertising (and elsewhere), ideology "is based on false assumptions."
Now hold on cause this gets a little twisted. We maintain that advertisers who expose the underlying metacommunication of ads do so not to demystify their false assumptions, but rather for the purpose of appearing to do so. Herskovitz calls this falsified metacommunication.