It's actually not dissimilar to my budget PV Mackenzie kilt which is pleated to the white grid because the sett (to the red grid) was presumably considered too large. It resulted in the white grid on the back being narrower horizontally than vertically and all the vertical red lines were hidden.

I also asked a friend, who made a couple of kilts when her sons were asked to be pageboys at her sister's wedding, about this technique in general and she offered an opinion that in a smaller yardage kilt, it may be done to increase the number of pleats.