Apple Iphone 11 Pro
What Render Engine was used?
The built in Blender 2.8 Cycles Render was used. If you intend to use Eevee with this model, extra setup and tweaking will be required.
Can I change the picture show on the phone display?
Yes, the process is as simple as changing the image texture in the shading panel and scaling the image in the UV editor depending on its resolution.
Are the materials PBR?
All of the materials are PBR except for the glass shader used for the front and back panels and as the camera lens.