Feels like they had a class discussion before each drawing. Its basically the same before and after theme. Before: white lab coat, glasses. After: 'normal' people. Not very scientific, excuse the pun.
It's kind of ironic because what kids are taught is that science is objective. Instead of learning that about science, these kids were fed dogma - which is way to common in 'science' these days.
http://ed.fnal.gov/projects/scientists/david.html