How does Harm de Blij use imagery in Why Geography Matters: Three Challenges Facing America?

Imagery:

"One year from now, the room in which you are reading this will be about a half inch (13 mm) from where it is today, assuming you are somewhere in North America."

Combine a shrinking population with rising life expectancy, and the economic and political consequences are alarming. In Europe, there are currently 35 people of pensionable age per 100 people of working age. By 2050, on present demographic trends, there will be 75 pensioners for every 100 workers; in Spain and Italy, the ratio will be 1:1."