Actually this isn’t new at all. Ever see a surveyor on side of the road? That instrument the surveyor uses is the exact same technology except it only gives bearing and distance. The rod the other guy holds is a multi facet prism mirror, it doesn’t have to be pointed directly at the instrument. That instrument is called a total station, it fires a laser toward the rods prism and bounces back information it collects. But as was said a killflash and other deterrent will easily defeat it, with killflash the scope could only be detected if it was pointed directly at the device.
Different optics. The multi-cube-corner mirror is designed to reflect any beam back at its source. Imagine if the intended use of the mirror were very directional, you could put an opaque tube on the front of it pointing in the desired direction. It would still serve the intended purpose but anyone off axis by a very small amount can't see the reflector. That's essentially what the killflash is, is a bunch of tiny tubes pointing on axis. No one off axis can see the lens (and thus a flash from the lens, and even on axis, the shine is broken up by the grid pattern.
If this device is emitting lasers in all directions, why wouldn’t an enemy launch a missile designed to hone in on something emitting lasers?
This device will only see a person if that person is looking at you since that is the only time you can see the reflection of their retina.