Is there an intuitive reason for the displacement map being rotated? also, if the base surface is 3d (as I assume is the case with this model/example), how does the displacement map work in terms of dimensions? thanks in advance if someone can help me understand :]

Is there an intuitive reason for the displacement map being rotated? also, if the base surface is 3d (as I assume is the case with this model/example), how does the displacement map work in terms of dimensions? thanks in advance if someone can help me understand :]