The corporate desk

Having worked in a few desk-bound positions in organisations, I recall the differing "standard" of desk decoration.

At the Chief Minister's Department, you'd get funny looks if your desk didn't have at least one photo of yourself pinned on the partition.

By contrast, at the ACCC, the standard appears to be undecorated desks (apart from papers strewn around).

How can two seemingly similar workplaces have such different conventions for personalising workspaces?