These illusions are invented by a Japanese psychiatrist Akiyoshi Kitaoka (A. Kitaoka). Without any trouble you can make your mind up, from which category of psychological condition you have to muddle through. Illusions are actually remaining at a halt for a calm and relaxed person. If the illusions seem to be in active shift then you need a holiday and lastly the worst case of all, if these illusions give the impressions of rapid changing then most appropriate place for you is the hospital.
I saw 2 of them moving.....UH OH.