Get to know the Duel screen

The screen title says Which one stays?
Both videos start playing automatically and replay when they reach the end.
Vertical and horizontal videos get equal space.
You hear audio from only the selected video at a time. When you switch sides with ← / →, the audio switches with it.
At the bottom, you’ll find the Enter keep this · reject the other and M keep both buttons. The ← → select hint also shows you how to change sides.
The × button closes the comparison without making a decision.
If a button has keyboard focus, Enter or Space activates it.