My experiences being humiliated in public by Mistresses has been varied but usually on the tame side of things compared to what is possible. What I've learned is that it really doesn't take much. A well-planned item can be enough to garner the desired effect and it doesn't have to be over-the-top to do so, both for an external reaction from onlookers and the internal reaction for the sissy.
I've seen items similar to these before but I guess you could call these "this year's model."
Even if mostly worn under a coat with the scarf ends running up the sleeves, the design leads to a constant state of self-awareness for the sub as every time they move their arms it will give a tug around the neck.
I guess you could think of them as a state of of mild bondage with a greater intent to humiliate than restrain.