Wouldn't it be easier to choose "Difference" as "Boolean Modifier" mode or is there a special benefit of using a Boolean cut with flipped normals on the cutting cube and "Intersection" as the modifiers mode on the duplicated bird?
No I don't think there's a benefit other than not having to switch the boolean modifier's settings. At the time I was probably less versed with boolean operations. Setting to difference instead has to be the more straight-forward method 😅