A patent showing improved eye detection for viewfinder showing conserving battery life based on how and when the LCD turns off.
From Canon News:
This patent uses a combination of sensors to detect if the LCD is open, viewable or tucked away to determine the distance thresholds automatically.
For instance, if you have the LCD open and twisted to the front, it's less particular about objects coming close to the viewfinder than it would be if the LCD is twisted and closed.
Anything to improve battery life is always welcomed.