Image of Edessa
French scholar Paul Vignon has listed fifteen similarities ("marks", like tilaka) between most of the icons of Jesus after this point, particularly in the icons of "Christ Pantocrator" ("The all-powerful Messiah"). He claims that these are due to the availability of the Image of Edessa (which he claims to be identical to the Shroud of Turin, via Constantinople) to the artists. Certainly images believed to have miraculous origins, or the Hodegetria, believed to be a portrait of Mary from the life by Saint Luke, were widely regarded as authoritative by the Early Medieval period and greatly influenced depictions. In Eastern Orthodoxy the form of images was, and largely is, regarded as revealed truth, with a status almost equal to scripture, and the aim of artists is to copy earlier images without originality, although the style and content of images does in fact change slightly over time.