The main reason being that the skinning machine by Skaginn, which was used for skinning the superchilled fillets, removes more flesh along with the skin as compared to the Baader 51 machine which was used for skinning the non-superchilled fillets.
Helsta ástæðan fyrir því er sú að roðflettivélin frá Skaganum, sem roðfryst flök voru roðdregin í tekur meira hold með roðinu miðað við Baader 51 vélina, sem óroðfryst flök voru roðdregin í.