The Pixel 3 XL will have a notch on the display and only one rear camera. Google is ditching the dual glass/brushed metal design on the back and is opting in for a glass panel from top to bottom.
The Google Pixel 2 XL arrived with OLED screen. Sadly we cant figure out if the panel here is the same, although it is very likely both the 3 XL and the regular 3 will finally go with the power-efficient screen.
The Google logo on the bottom looks off since this is an EVT 1.0 unit, or just after the first level of engineering validation test. This is when the R&D team combines looks-like and works-like prototypes in a single unit to match materials and internals, before going into manufacturing.
Therefore, we might see some minor differences in the appearance, but the main aspects like the notch and the single camera will stay.