What it most likely means is that your plant is making a sport. Can I have permission to show this photo to some other people?
No one knows the exact breeding lineage of White Princess, White Wizard and White Knight, the trio of green and white variegated Philos that are considered 'cousin' plants. They have been around for 10-15 years, I have had my White Wizard that long, but have not been all that popular until the 'new aroid/houseplant' craze hit, now they have become very expensive.
But the lineage of Princess 'most definitely probably' contains the genetic quotient for Pink Princess or another red-hued Philo. (The difference between Princess and Wizard is that Princess has the pink flush to the stem, and Wizard has no pink).
Variegation in plants arises in the meristem tissue, the trunk. It is translated from the trunk up the petioles (what most people refer to as the stem) to the leaves. The more non-green pigmented cells that exist in the meristem, the more variegated the leaf will be. It looks like your plant is translating pink along with white.