But the editor who placed this tag here didn't say why.
Talk about it here.
In 2010, he saw Iris Wildthyme, Panda, and Elspeth May in the Celestial Omnibus after they attended a book launch party on Shaftsbury Avenue. He drew a sketch of them with crayons and felt tip markers. This sketch, which he titled "Relaxing on the number 22", was later kept in an art exhibition dedicated to Iris' life. When Panda saw the sketch he was appalled that it was kept in the exhibition. He declared that Mann had "no visual talent at all". (PROSE: Iris at the V&A)
In 2015, Mann attended the San Diego Comic-Con. When the Twelfth Doctor went through the convention taking selfies to find the Lady of Neverness, he took a selfie with Mann which had the Lady in the background. (COMIC: Selfie)