I voted for corner camera. A camera located towards the corner has following benefits: * Holding the phone horizontally in everyday usage has a lower likelihood of accidentally touching the lens, which would leave traces that have to be cleaned. * Ability to hold the phone horizontally in a more stamina grip without blocking the camera with the fingers. * Macro photography can be closer to the ground or a corner. * More efficient usage of physical space, because the other hardware components do not have to be built around the camera module. The only benefit of a middle camera I can think of is for the sake of a symmetrical design, which is not even a practical one.