What does "as parentheses" mean in this context? Does it mean "as something added to..."?
Rituals and ceremonies are expressive occasions. As parentheses in an ordinary workday, they enclose and define special forms of symbolic behavior. What occurs on the surface is not nearly as important as the deeper meaning communicated below ground. With little time for anything not related to the task of building the machine, the Eagle Group intuitively understood the importance of symbolic activity. From the beginning, leadership encouraged ritual and ceremony.
Source:
Reframing Organizations: Artistry, Choice, and Leadership by Lee G. Bolman, Terrence E. Deal