Sundered flesh is not working on armour.
It should do what happens on weapons, which is make other weapons look like the raid weapons.
The shader does not do this on armour. it should be the same as the raid armour shader but it has been messed up and instead on other armour it's this random horrible shader that is completely different and in no way relevant to the shader thumbnail shows up for sundered flesh.
It should look same as below: