Sorry this is not a U.S. coin but it just reminded me I've been meaning to ask about this kind of effect (?) that I see on coins sometimes, and I don't know which forum I would ask in, regardless of photo. It appears the round outline of King George's head is visible on the reverse, but it's soft, unlike the hard lines of a die clash. My guess would be that it occurs with normal dies but something different about the squeeze? Am I wrong and it's just a type of clash? If not, is there a name for it, and is it considered an error?

*** Moved by Staff to a more appropriate forum. ***