“Interlocking Board of Directors”

What if there is an “Interlocking Board of Directors”? (Mizruchi, 8/1996). This entity refers to the practice of members of a “corporate board of directors” that serve on other “corporate boards of directors” for multiple corporations at the same time, e.g., a board member on McDonald’s board “interlocks” (or serves) as board member of Burger King’s board. Could this be? What’s wrong with this picture? Why? Why not?