During the bear chorus line with bears arm in arm (31 minutes into the feature), which arm is in front changes a few times.
During the "Mickey and the Beanstalk" feature, the house breaks apart as the beanstalk grows (at around 53 minutes) and the vines carry Mickey, Donald and Goofy upwards as they sleep. But a minute later, a shot of the intact house can be seen being carried into the clouds by the beanstalk again.
Willie the Giant's face stubble changes from flesh colored, as seen during the "Mickey and the Beanstalk" feature, to white/gray around his mouth when he lifts Bergen's roof looking for Mickey.
During the "Mickey and the Beanstalk" feature, the giant dragonflies are spotted overhead (at around 55 minutes) and Donald exclaims "Bombers!" then mimics shooting at them with a machine gun. The story takes place long before such things existed.