Miss Mimi says that her favourite birds are bluebirds, and asks for a 'bluebird bonnet' she sees in a shop window. But the bird on the bonnet is clearly a crow.
In the saloon scene where Mr. Edward's is discussing Johnny with other saloon patrons: you clearly see an auto playing piano. This invention was in 1896 by Edwin Votey.
When Johnny is asking a man for a job, the man is sweeping a set of white wooden steps. As he sweeps, he breaks a large piece off part of the steps leaving a big hole right in front of him, but he just walks off without acknowledging or attending to it.
After Johnny leaves home, Charles says the good thing about having girls is that they won't run off. However, earlier in the season in "The Lord is My Shepherd", Laura did run away after the passing of Charles Jr.