Final answer:
The president of Pepsi Company acts in a figurehead role when speaking at a retirement dinner, embodying the company image in a ceremonial capacity according to Henry Mintzberg's managerial roles.
Step-by-step explanation:
The president of Pepsi Company giving a keynote speech at a retirement dinner for a long-time bottler is an example of the figurehead role. In this function, the president is acting as a symbol of the company, involved in ceremonial duties that reflect the company's image and serve as a representative function rather than direct involvement in daily managerial tasks. This role is one of the interpersonal roles in Henry Mintzberg's managerial roles, where a manager acts more like a symbol than an active decision-maker in certain situations.