How is the former different from the latter? Is that not still science? Are you not doing science if a teacher directs you to perform experiments for a grade?
The point of mixing the chemicals and doing the procedure yourself is to understand it properly. Just being told about it in vague terms is far inferior in terms of learning.
It becomes a mere 'demo' once you're well-practiced in the specific procedure. And she wasn't.
It makes no difference with respect to her punishment. It was unfair no matter what. I'm just pointing out the technicality.