New Delhi, Oct. 3 -- You're on a weekend getaway in Himachal with friends. The sun sets, the crisp mountain air rolls in, and instead of retreating indoors to crowd around a phone screen, you pull a compact device from your bag, point it at the side of your car, and instantly launch a massive outdoor movie night under the stars. This isn't a tech fantasy, it's exactly how the next generation is rethinking entertainment.

If you still think the ultimate viewing experience revolves around a massive television bolted to a wall, you might be stuck in the past. For years, the prevailing wisdom has been that a TV paired with an expensive soundbar is the undisputed king of the living room.

Projectors, critics argued, were fussy, required pitch-...