On a flat expanse of reclaimed land in Osaka Bay, Japan has been busy preparing to stage a vision of the future.

This Sunday, the gates to the 2025 World Expo will officially open on the human-made island of Yumeshima (which translates, perhaps a touch optimistically, as “Dream Island”), kicking off a six-month extravaganza featuring pavilions from more than 160 countries, territories and organizations.

The theme is lofty and somewhat indistinct: “Designing Future Society for Our Lives.” But what that means — and whether visitors will buy in — remains unclear. Rehearsals held last weekend offered glimpses of both promise and peril: immersive displays that sparked wonder, alongside long lines, buggy smartphone apps and an unnerving gas leak. Attendance may well pick up (so far, buzz has been noticeably absent), but a larger question looms: Can the expo format — born in the 19th century as a pageant of empire and industry — still matter in an age of virtual connection and climate concerns?