The way I understand this (Iwama background) it is not 'omote when we move in front of uke and ura is about to move to rear the uke'.
Omote is when the techniques is executed when the uke is facing you (more or less) and ura is when uke faces away from you (more or less).
Typically the uke gets this or that way, because
you move them into that position.
Omote:
https://www.youtube.com/watch?v=V4c67YE4mk0