I bought a Wrigley bathroom cabinet from Taobao, and there was a crack on the back of the AA ceramic basin. Please look at this picture. Is this normal?

Please feel free to use. No problem. This crack is not damage and has nothing to do with logistics. It is naturally formed in the process of firing porcelain, because it is a strain concentration area of the structure and will crack at the early stage of high temperature. I have seen more terrible cracks than this, and thin chopsticks can be inserted.