How was mae-sumi-otoshi performed?

Recently we had some discussion in our dojo regarding the difference of uki-otoshi and sumi-otoshi. The result was pretty obvious, and that is basicly the direction of kuzushi, whereas the biomechanic principles of the throw where almost identical, just in different directions, since uki-otoshi can be performed while Tori is facing the same direction as uke. In uki-otoshi uke has his balance broken to the front right/left corner, whereas in sumi-otoshi it is in the backwards right/left corner.

However, during my research on the matter I've found an interesting snippet of text in the Kodokan throwing techniques, by Daigo-sensei.


How was this "mae-sumi-otoshi" really performed? In sono-san application 2, it looks very much like the uki-otoshi where tori is facing the same direction of uke.

Here is sumi-otoshi explained in the book of Jigoro Kano shihan, Kodokan Judo.