Can someone try to explain this?

[holymario]

This is a short clip of something I don't really understood :| Why did sheik get hit from nosferatu when I (accidently) made a reversed one? Or is the hitbox just larger than I though :|
https://www.youtube.com/watch?v=d0CfN7Ij-2o

 

[FieryRebirth]

Luck and skill. Shiek's FSmash pushes her forward a bit and you pushed her the moment you executed a well-timed Nosferatu at her new spot.