This is a minor cutscene.
After beating Level B-13, a cutscene will begin in Level B-12 featuring the Child and the Student. The Child asks the Student why she doesn't have a lab coat although she's a scientist. She answers that she doesn't need one, and to justify her answer, she begins to explain what science is until the Child stops her.
He complains that school science is boring, and tells her to talk about movie science instead. The Student tries to protest that "school" science doesn't have to be boring. The Child ignores her, saying that all his teachers say that too, but they're wrong. When the Student tells him that she could be the exception, the Child just says "No thanks. I don't need science anyways." The Student mumbles "Oh, so that's why..." then out loud she responds, "Let me get back to you on this."