[Luc]

The camera could be built into a see-through part of the edge, kept horizontal by a small motor driven by the accelerometer.

This way you could just 'shoot from the hip', looking down on your tilted tablet like you would look at the screen of one of those old Hasselblad cameras.

The screen is large enough to hold at some distance from your eyes, after all!

[gaius]

They still make 'em, with digital backs. For a lot of types of photography waist-level finders (WLFs) make a lot of sense. For example, you usually want to shoot people from their eye level or slightly below, with an eye-level finder you might find yourself kneeling a lot...