  In this paper, we study wall elements of rank 2 cluster scattering diagrams
based on dilogarithm elements. We derive two major results. First, we give a
method to calculate wall elements in lower degrees. By this method, we may see
the explicit forms of wall elements including the Badlands, which is the
complement of $G$-fan. In this paper, we write one up to 7 degrees. Also, by
using this method, we derive some walls independent of their degrees. Second,
we find a certain admissible form of them. In the proof of these facts, we
introduce a matrix action on a structure group, which we call a similarity
transformation, and we argue the relation between this action and ordered
products.
