Silliness. It is the blanket thing for anxiety, not because it is a costume. A blanket/dog coat would have the same effect. Like “thunder shirt/coat” for dogs.
They also use very weighted blankets for people with anxiety.
All the same.
I love my 13 lb weighted blanket, I sleep with it every night I also bough a 6 lb blanket for my grand son. He loves his too.