Jones, so you're thinking those are 1/2" chains and not 3/8"?
Magnus, there's only a pair of binder/chain assemblies on the rear. DOT guidelines say that you need .8 gees worth of holding force on the rear of the vehicle to prevent forwards movement. The front chains (or each corner) are to stop side to side or rearward movement. Or, all together, in the event of an accident to keep the load on the railer.
Hmm, just noticed two other problems. One of those rear shackle hairpins looks like it's just stuck in and the left side tool box on in front of the fuel tank is open/flapping in the wind.