Ok, it is a party trick. And Demetrio's comment is valid too - my understanding is Tohei developed this as a quickly learned example of how the mind can affect the body for more power in movement. This exercise was created as part of a shortcut, compared to O Sensei's teaching style. The imagery helps take antagonistic muscles out of the posture and helps with some alignment issues.
I do take it a bit further and lean in the outstretched hand from in front, and make the point that proper alignment goes down to the feet.
Having "got it" once in a stress free environment, eventually this becomes something like shomenate in motion and with proper timing and that takes practice to become a default alignment.Shodokan and Yoshinkan seem to do very similar things in a slightly different way.
Not a principle then.
Tohei had principals and whether you agree or disagree with them, they are principals. They are principals in the sense that one can validate or correct their (Aikido) activity vis a vis a principle : did I kept my weight underside - not so much, will work on that.