Looks just fine, you have laser on one side and receiver on other side.
Light emitted by laser is bounced back to receiver and distance to object is calculated by the time spent between emitting and receiving.
The laser focus will only work effectifely within 0.6 meter but can be used up to 5 meters (with varying results) If laser focus doesn't work the camera falls back to another focussing method (phase detection most likely)