I am not saying that the clip is torturing the cat, but it is a way of controling the cat.
What happens when assholes put that on a cat to see what heppens and then does not take it off?
That technique can be used to subdue a terrified cat to give it needed medical care or to torture it.
I agree . . .
I don't see that the problem lies with the technique . . . but with the motive for using it.
There are already myriads of ways assholes inflict torture on animals . . . most are a whole heap worse . . . and that is a problem in itself.
To carefully use this technique for a legitimate purpose seems intelligent and kind to me.