This site is a hoax.
I worked for a veterinarian in Portland a little bit, and these cats are not exhibiting any signs of anxiousness. If they were frightened, you would see eyes wide open, huge pupils, ears possibly laid back, fur ruffled, etc. What they look like, despite their being in jars, is that they are playing or asleep. It's a sick idea, but it ranks right up there with Weekly World News, or The Onion. It's designed to be shockingly funny.