The 'no opposing wall' guide is generally a function of non-control room spaces. Symmetry is key in control rooms.
Regarding space between panels. Far too many variables. However, let's look at control room, first reflection reduction.
- is the gap between panels significant enough to allow ray energy to reach it? (this is not only variable by the width of the gap, but also the thickness of the panels)
- if yes, then is the thickness of the 'next' trap sufficient to contain the reflection, given angle of incidence?
-if yes, does the panel's construction allow for absorption on the sides?
Based on visual cues alone, I would hazard to guess that the photo linked in the op would be subjected to first reflections to the left and right of seated center... I.E. fine for a mix position, but inadequate for a mixing 'zone'.