The documentary contains a major error, as the photo of a naked girl supposed to be Lorina Liddell is actually a photo of an anonymous girl. The original photo is located at Musee Cantini, Marseilles. Lewis Carroll isn't the author of this photograph and the true photographer is unknown.
UK-based Lewis Carroll Society featured a comment by Edward Wakeling in their newsletter "Bandersnatch", issue 166, that states many contributors were betrayed in the process of making the documentary. According to this text, the documentary turned out to present a different image of Carroll than some contributors expected - and it was a misshapen one. "The Secret World of Lewis Carroll" was described as "unkind, unfair, and untruthful" project.
The photo of a naked girl featured in the document and mistakenly presented as Lorina Liddell was described as a portrait of Lorina by Alexandre Révérend. This French musician served as an identifier for Musée Cantini despite having no experience in identifying photographs or historical research - he was appointed for this task due to his personal interest in Lewis Carroll which included some French translation of his writings and editing a collected works of Carroll by La Pleiade. His involvement in misinterpretation of the anonymous photograph was not investigated in the BBC documentary.