“I do not know whether a philosopher has ever dreamt of a company engaged in the home delivery of sensory reality,” wrote the French poet and essayist Paul Valéry in 1928.

He was intrigued by the idea: “It will be wonderfully pleasant to be able to transform at will an empty hour, an interminable evening, an endless Sunday, into an enchantment, an expression of tenderness, a flight of the spirit.”

Home delivery of sensory reality is now engaging many companies, from Walt Disney to Netflix and ByteDance, the Chinese parent of the 15-second video platform TikTok. High-definition images will soon appear as holograms or pictures on virtual-reality spectacles. For now, most are displayed on flat screens large and small — cinemas, televisions, tablets and phones.