This design poses a couple likely (economically) unsolveable and unanswered questions:
What about adaptive brightness? With no camera/light sensor at all at the front, the only way to sense ambient light is through the "rear" camera, but that camera will be facing opposite to the screen most of the time, so imagine you're facing the sun: the camera, at the back, will be under direct sunlight, so it will increase brightness when you least need it, since the display is now in the shadow; but when you have the sun on your back, the camera will be in the shadow, so it'll dim the screen when you most need increased brightness, since the screen will now be exposed to direct sunlight.
Also, what about attitude sensors? Some photo apps record camera orientation and inclination (x, y, z axis), but these sensors are located in the phone's body, so what happens when the camera is rotated? You'd need the camera app to be aware of the camera's rotation angle, to be able to compute the real photo orientation, but for this it'd probably need a specific api support to gather that info; so will it even be possible? The alternative would be a second set of orientation sensors on the camera module, but that would likely be too expensive for a middle range phone such as this, and just for this specific purpose. Having the sensors exclusively on the camera module wouldn't be a solution either, as then it would throw off orientation readings for every other purpose, if the camera is rotated.
Hopefully, NotebookCheck will be able to address these issues, when they test this phone.