The date looks normal to me.. Sometimes a little bit of a worn Die could cause a bit of odd appearance but it is really nothing. Your question just reminded me of a silly kid joke.. Why was 6 afraid of 7?... Because 7 8 9 7 (ate) 9
Dies are made from a hub that has the date on it. Therefore all dies from the hub will have the same spacing. Your coin is the same as all of the other 1957-D coins minted BTW: The mm was added to each die individually until 1989, so you may see lots of variation in the location
