(Subsection of Unknown. This was created by the original wiki author in 2010.)
A hypersigil is an large or medium sized artwork with magical intention, designed to manifest events or objects in the objectively observable reality.
It can be a book, a picture, a painting, a movie or any medium which requires a sense of symbolism, interpretation, aestethics.
It is larger than a sigil hense the extension hyper- which was popularized by Grant Morrison on the Disinfo Con DVD in which he explains the use his comic series The Invisibles has as a hypersigil.