In Fushukuhanpo, The drum and bell are sounded for breakfast and lunch. "At this time, if there are people sitting facing the wall they must turn and sit facing the center," ie, for the meal. p. 83
It's even clearer in Bendoho, Model for Engaging the Way, aka how to get through the day in the monastery --- p 64: "For evening zazen, when you hear the bell, put on your okesa, enter the monks' hall, settle into your place, and do zazen. The abbot sits on the abbot's chair facing [the statue of] Manjushri and does zazen, the head monk faaces the outer edge of the sitting platform and does zazen, and the other monks face the wall and do zazen."
Dogen is quite consistent on this --- after the evening and night, and early zazen, when the umpan and hans sing out the beginning of the monastic day, "gassho to the okesa . . . and place it on the top of your head" and chant the robe verse. Then, "after putting on the okesa, turn around to the right and sit facing the center." p 70
A little later comes breakfast, and a while later the han sounds for morning zazen. "The head monk and the assembly, wearing their okesas, enter the hall, and [the monks] do zazen facing the wall at their places. The head monk does not face the wall . . .". p 70.