It looks to me like it was cleaned, possibly with a silver-polish cloth; good for silver bowls and tea sets, but bad for coins. I used one long ago, results looked just like that. If it had been dipped, there would not still be toning/dirt inside the crown, letters, nooks and crannies.
Hopefully, it will only be a lick-the-thumb-and-rub cleaning, which wouldn't really hurt it too much.