"The techniques used in the Mona Lisa are known as
sfumato and chiaroscuro. Sfumato (deriving from the
Latin word for "smoke") , describes the smoky
atmospheric effects from the transitions between
colors. It is evident in the delicate gauzy robe and
in her enigmatic smile. The other technique,
chiaroscuro, refers to the modeling and defining of
forms through the contrast of light and shadow."
Now the problem is solved. If she got her information
from a different source, then she can write to them
and have them make the correction.