Smartphone manufacturers often make “dummy” units to the exact specs of their upcoming hot devices. These are distributed to accessory-making partners to make their job easier and help them have products ready as soon as the phone launches. For example, popular case makers can score a dummy to test their new case models against and be ready with any corrections well before the handset is actually announced.
Of course, footage of such dummies will sometimes leak and it looks like this has just happened with a Galaxy S9 dummy unit. At least that’s what the person who leaked the video claims.