Wow you guys are thick. The guy is clearly not using a tripod in a few scenes and the subjects don't change positions, so the jerkyness is actually the camera not pointing straight at the scene because of a lack of a solid base. This is what the author was referring to.

My girlfriend had one for her fish, but it was really hard to clean some of the nooks. Also, the fish would often hide and sometimes even cut itself on the sharp edges!