For example, you may both contribute ideas to product vision, or you may both have ideas about how the team should execute/prioritize/set goals. This is okay and actually expected, especially at more and more senior levels where all roles regardless of discipline basically converge because your scope grows to own more and more of the entire problem/product area/team rather than any one facet of the problem. The PM role may overlap with both the designer and design manager roles (typically more the latter.) They may also overlap with engineering managers and tech leads.