A young man wearing goggles is putting some liquid in a beaker while a young girl wearing blue gloves looks down while holding a pen.
A science teacher demonstrates how to mix the liquid as his young student takes notes.
The man could have been a student as well instead of being the science teacher who's demonstrating. The young girl could have simply been holding the pen without any intention of taking notes.
There is no evidence in the first sentence the young man is the science teacher or that the young student takes notes.
A person can help someone with science without being a science teacher.