Have you ever had a kitten? LOL most all of them enjoy sqeezing into tiny tiny spots.
Our full grown cat will force itself into a ten gallon tank, a five gallon tank, cereal boxes, fish bowls, boxes, anything. On her own free will.
A neighbors cat LOVES to get himself into plastic shopping bags and be carried around. He goes in, you grab the two handles and he lays there, for HOURS sometimes even though it looks like he can't breath.
I could photogrpah this entire thing and do the same website, and a bunch of people would call me "inhumane"
Also- clearly, no child was IN any jar.
Its a JOKE. I don't think its "mean" at all. There are far worse "mean" jokes out there that people enjoying watching. Look at JackAss. lol