For starters, while the E3 demo ran at 1280 x 720 pixels in docked mode, the new demo has bumped that resolution up to 1600 x 900, the same target resolution as Breath of the Wild. (nintendowire.com)
This is why checkerboarding is actually considered a native 4K output when that is the target resolution. (n4g.com)
Both the base Xbox One and PlayStation 4 will have a target resolution of 900p, so it's quite the jump for Xbox One X owners. (video-games-galore.com)