We care more about things in near view, vs. far view. So getting you to see your future self in a more near mode helps you to care about helping that future self:

Tessa Price, a 22-year-old college senior, is gazing into a mirror in a virtual-reality laboratory at Stanford University. Looking back at her is Tessa Price—at the age of 68. Staring into a mirror today and seeing yourself as you will look in the year 2057 is unnerving. But that may be just what it takes to shock Americans into saving more. … In one experiment, young people who saw their elderly avatars reported they would save twice as much as those who didn’t. In another, students averaging 21 years of age viewed avatars of themselves that smiled when they saved more and frowned when they saved less. Those whose avatars were morphed to retirement age said they would save 30% more than those whose avatars weren’t aged. … Getting specific. … When people spend three to five minutes imagining and writing down how they would feel in a comfortable and worry-free retirement, they become roughly 25 percentage points more likely to increase their savings on the spot. (more)