I think you should put this,, This is from my way. for me not mirror at player mean it is face to the right
-Player on collusion with Crate > Crate.X + 2
Player mirror is invert or Player go right (another condition)
if the player is from right and your character is not mirror
-Player on collusion with Crate > Crate.X - 2
Player is mirror or Player go left(another condition )
when player is mirror
here -2 and +2 just to make the crate move smothly also dont forget the crate need to be solid