The guide in the purple cardigan has a microphone curled against her cheek, and the young man in the grey hoodie has a receiver tucked in his ear. Between them hangs a painting that could have used her in 1893. When Paul Gauguin’s Arearea first went on show in Paris, it carried a Tahitian title almost nobody in the gallery could read. No one stood beside it to explain. Gauguin painted it in 1892, about a year after he sailed for Tahiti looking for a way of life he thought Europe had lost.