I remember interviewing Eggers when THE WITCH came out and he was so bothered that the family eats around a 3-wick candle in their home because it was the only way he could get enough candle light in the scene but IT WAS NOT A PERIOD-ACCURATE CANDLE.
I dunno if this is standard but our showing of Look Back had an interview with the director and cast at the end, and the director mentioned that in addition to leaving a lot of draft lines in the final animation he allowed the design of the characters to naturally drift from