not sure I would ride it. the rear wheels need a spline instead of just a nut for friction to connect the rear wheels. Also it will hobble around corners if both wheels are driving.
The nut isn't providing drive friction. The disc bolt heads align into holes on a boss attached to the axle for the drive. It does look like a 2wd axle though
Ah yes, that's a ratcheting drive.
Unlike a differential, this does not split the difference properly and would only be slightly useful on an upright granny trike. On a bent.... no point at all with this system.