Tess Thackara considers Sandra Lousada's extraordinary photographs of visitors to the 1961 Mark Rothko exhibition at the Whitechapel Gallery.

Thackara writes: "Often compositionally beautiful, the black-and-white images reveal onlookers lingering before paintings, leaning against gallery walls and columns, lazing on benches and soaking up the environment of Rothko’s work. Many appear lost in solitary reverie, while others lean towards others to share thoughts."

Rothko in Britain is on view at the Whitechapel Art Gallery, London through February 26, 2012.