The New Yorker, in Judith Thurman's piece on Leni Riefenstahl, addresses the issue of seductive art caught in a lie:
Riefenstahl’s “genius” has rarely been questioned, even by critics who despise the service to which she lent it. ... Yet one has finally to ask if a creative product counts as a work of art, much less a great one, if it excludes the overwhelming fact of human weakness. That fact is the source of soulfulness and dramatic tension in every enduring narrative that one can think of. A seductively exciting surface, such as the morbid spectacle of a mass delusion, may distract from, but cannot insure against, a slack core, and in Riefenstahl’s case a handful of sequences singled out for their formal beauty and a quality that Sontag calls “vertigo before power” have achieved an influence disproportionate to their depth or originality.
Tim Rutherford-Johnson has had similar questions on his mind lately.