The artworks - which include a version of his giant bubble dog and a large multi-coloured pile of Play-Doh - are shown as augmented reality exhibits superimposed over real-world views captured by smartphone cameras. Facebook announced plans for a similar feature earlier this year but has not launched it yet. Early reactions have been mixed. The Techcrunch news site visited one exhibition site in New York's Central Park and reported experiencing glitches when it tried to view the imagery.