 The "New Yorker" article discussed the troubling circumstances in which Kemp attributed this work to Leonardo.But apart from this, strong indications are going against the hypothesis of authenticity, and the attribution to Leonardo has been challenged by a number of scholars who showed interest.Among the reasons for doubting its authorship are the lack of provenance prior to the 20th century – unusual given Leonardo's renown dating from his own lifetime, as well as the fame of the purported subject's family – and the fact that it was on vellum.