LONDON — “One unexpected spinoff of [Jan van Eyck’s] Arnolfini portrait, is that the convex mirror became a staple of the middle-class interior, there became a fashion for these mirrors from the 1860s onward,” said Alison Smith, curator at Tate Britain. “I think its because they helped create an ambiguous, mysterious space.” In this video, curators explore the connection between different notions of realism and the use of mirrors to explore another level of dimension and perspective. The National Gallery presents “Reflections: Van Eyck and the Pre-Raphaelites,” running through April 2, 2018. For more information, www.www.nationalgallery.org.uk.