What is the importance of the portrait of the King on the wall in the apartment in Dolphin Square in the novel, Transcription?

The portrait of the King on the wall in the apartment in Dolphin Square is an ironic symbol of the true identity of Godfrey Toby and MI5's surveillance of the fifth columnists. When Juliet asks Perry about the portrait, wondering if the informants might think it odd, he declares that "they will believe it's all part of the disguise" (45). It is a blatant admission of the truth (that Toby is a British spy, loyal to his country) masquerading as camouflage. This dual meaning aligns with the novel's theme of doubles.