Hitchcock's Cynicism.

From Alfred Hitchcock's "The 39 Steps", 1935.

A businessman holds up an artifact; there is demand for brassieres and profit must be made so we shall sell brassieres.  At the same time, under the guise of commerce, he and his companion will winkingly indulge in a little titillation.  The man's wry expression typifies Hitchcock's attitude toward sex in his films.  He knows that the salivating hordes want innuendo, that a glimpse of stocking will increase the box office gross, so he will provide it but at an arm's length.  He would never be so base as to actually be aroused by it (wink).  The viewer is doubly manipulated: Hitchcock satisfies our appetite for sex while simultaneously flattering us by letting us in on the joke.