Any animal is unsure of a new place. How they react to it is different depending on animal breed and species, specifically dogs vs. cats. Dogs more or less will tend to rush in and scope out the studio and keep moving while cats will slink around and crawl under something to hide—be it a couch ion the front area or behind the backdrops.
No matter how super laid back and cool you think your cat is it is a whole new ball game bringing them to a place where they can smell other people and animals. That’s why we never rush animal portraits and let them have time to find their way around and decide what works for them. Especially with cats. They more or less will come when they feel like it while dogs can often be coaxed with a snack.