So far all of the thermal weapon sights use digital reticles, this means the power is down the sight becomes a broken TV. Nothing but darkness. Either it is powered up in thermal imaging mode, or nothing.
Steiner solves this issue by projecting the thermal image to the reflex sight. This means if the thermal is not working, the sight will still function as a regular reflex sight. This is a very smart idea. The user can turn the thermal image on and off, while maintaining the sight picture. The user can also see through the thermal imaging super imposed over the normal sight picture, and get more "understanding" of the image.
Obviously this thing is still a prototype, as you can see the rapid prototyping techniques used in making the bodies. The only down side is the thermal sensor is too close to the receiver, this means the top of the rail and handguard have to be clear of any obstructions in front of this device.