  Growth in crystals can be { usually } described by field equations such as
the Kardar-Parisi-Zhang (KPZ) equation. While the crystalline structure can be
characterized by Euclidean geometry with its peculiar symmetries, the growth
dynamics creates a fractal structure at the interface of a crystal and its
growth medium, which in turn determines the growth. Recent work (The KPZ
exponents for the 2+ 1 dimensions, MS Gomes-Filho, ALA Penna, FA Oliveira;
\textit{Results in Physics}, 104435 (2021)) associated the fractal dimension of
the interface with the growth exponents for KPZ, and provides explicit values
for them. In this work we discuss how the fluctuations and the responses to it
are associated with this fractal geometry and the new hidden symmetry
associated with the universality of the exponents.
