First let's address what makes this a Genesis, and the most clearcut sign is on the wheels where the brand's logo appears in the center caps. But that's not all. The other clear indicator is the crossover's stretched front end. There are several inches added to the fenders and the hood, and they push the front wheels farther forward than on the Santa Fe Sport. This significantly lengthens not just the nose but the amount of space between the base of the A-pillar and the wheels, a classic sign that the engine is mounted longitudinally to primarily power the rear wheels. And the only such vehicles from the Hyundai brand (Kia Stinger excepted) are from Genesis. In the case of this particular prototype, we know it's all-wheel drive thanks to the info sheet in the window, but this layout suggests that it's a rear-biased system, and a plain rear-drive version might be available.
That sheet of paper in the window reveals some other curious information. We can tell from it that this is all-wheel drive and has an automatic, and the "3.5" surely indicates the engine displacement. But there aren't any Genesis models currently using a 3.5-liter engine. The closest engines are a naturally aspirated 3.8-liter V6 and a twin-turbocharged 3.3-liter V6. Even looking at Hyundai's U.S. lineup, the only V6 in use is a naturally aspirated 3.3-liter unit. So it's possible this prototype is using a bigger version of one of the 3.3-liter engines, or perhaps a smaller version of the 3.8.
As for the size, we're going off of that Santa Fe Sport sheetmetal. The Santa Fe Sport is the middle crossover from Hyundai, fitting between the three-row Santa Fe and the two-row compact Tucson. All of the extra length in this crossover is only in the engine compartment, so the interior space is still going to be about the same, and as such will probably be a midsize two-row for Genesis. And we know that Genesis will have something in the middle since it announced both bigger and smaller crossovers to go along with a GV80-sized crossover. And the small one is expected for 2021, so we'll likely see this midsize model show up sometime next year for the 2020 model year.