I have purchased many miners from Bitmain, S1 and S2. Never has one appeared to have seen any use. In fact, they were so clean and unscarred I wondered if they had even been functionally tested. But I have yet to have ever had a DOA or failure of any kind.
Indeed, same experience. But perhaps the last miners that they sold for 0,4xx BTC where used in BITMAIN's farm... Looked exactly like this, maybe a little worse (picture from another user with the same experience as me).
Didnt take my own pictures, i had other things going on and its not like i had recourse.
Looks similar to the seasoning salt that Yifu shipped my Avalon with. Bastards mined with the hardware for months on end...