ラッピングの基本とマナー / 浅い箱、深い箱、正方形、慶事用と弔事用

[@darthlaurel]

Aren't the left and right sides relative to how you are holding the package?

[@tsutsuming]

Perhaps. When you place the package on wrapping paper, then face toward them, the side of right hand would be right, and the side of the left hand would be left.
It might be easier to watch the English version for you (?).
ua-cam.com/video/2Vc9VAyrZiA/v-deo.html