LONDON — This week Harrods and Gaurav Gupta hosted a theatrical couture evening inspired by the Ramayana, blending fashion, movement, light and storytelling to mark Diwali. The evening anchored the Indian couturier’s showcase of festive wear, which is available in a private suite at the Knightsbridge store through Nov. 2.

Gaurav Gupta’s festive season trunk show by at Harrods .

The showcase is the fashion centerpiece of a storewide Diwali campaign that runs from October through Nov. 8, with a special Diwali Gift Box, live music, retail theater activations and a Diwali-inspired light display on the facade. It also has a commercial logic.…