Symmetry in the control room it´s very important, it affects the stereo image and the information coming from both speakers.
If all reflections and bounces of the room that monitors are transmitting arrive later from one channel, we will have coloration and distortion, plus a stereo image degraded. The room will be ideal if you maintain parallelism, like textures or types of materials.

Avoid put reflective material in one side and absorptive in the other, on First Reflections Points.