This is one of the ceiling diffusers in my studio. By far the most common question about these (and diffusers in general) is "Is it just random?" These are actually carefully studied and calculated acoustic tools. This one is a "Primitive Root Diffuser" based around the prime number 157. They work by differing the distances to the reflecting surface of the wall (or ceiling). This gives the reflected wave lots of phase shifts relative to each other, creating a scattered or diffused field rather than a direct reflection (if it was a bare surface) or an absorbed one (if there was a baffle of some kind). I like to call them "Perfectly Random”. See below for a quote from the patent on these.⠀
"A prime number N is chosen such that N-1 has two co-prime factors which are non-divisible into each other. From the prime number, a primitive root is determined and, in the preferred embodiment, an algorithm is used to determine sequence values for each well. Each sequence value is proportional to the well depth, with each sequence value being multiplied by the design wavelength and then divided by 2N to arrive at the actual well depth value"