What is the choice of organizational chart? What motivates the choice?

The organizational chart you are looking at is that of Air Transport Association of Canada (ATAC), also known in Quebec as Association du transport aérien du Canada du Canada. This type of organizational chart shows the functional organizational structure. The motivation for choosing a functional organizational chart is the need to clearly differentiate the levels of leadership, management, and departments in the organization.
Starting at the top, each organizational level is identified by its function and the position holder. For example, the highest level function under the Board of Directors for ATAC is President and CEO, a position held by John McKenna, and one of the next-level vice president functions is Executive Vice President and Vice President Atlantic Canada and British Columbia, a position held by Les Aalders.
A functional organizational chart shows how authority and hierarchy is structured according to the function of different positions and departments. It also shows each is organized and operated independently of the others. For example, ATAC's Communications department, headed by Francois Roquet, is independent of the Commercial General Aviation department, headed by Wayne Gouveia.
A functional organizational chart may also show vertical and horizontal communication. Vertical communication is upward and downward communication between lower levels and higher levels of an organization. Horizontal communication is communication across one level of an organization, such as across the level of all Vice Presidents of ATAC. This ATAC functional chart indicates the vertical communication between functions, such as the communication of Executive Assistant to Vice Presidents, Danielle Lavoie, reporting vertically to Aalders, Skrobica, and Gouveia.