[throwhauser]

What does it do that can't be accomplished with something the size of a remote controlled car?

[hermitdev]

Pure speculation on my part, but having it around 5 feet tall is presumably for the optical cameras to have a better view of the majority of adult human faces. If you're talking a remote control car (at least like the one I had as a kid), any camera is either going to get great photos of people's ankles & shins, up their noses if they're close, or lose detail because they'll have to be too far away to get a decent angle to look at a face.

[joveian]

Above skirt height is hopefully more than just a good idea for a camera with a upward view.

[mcguire]

It's more intimidating. (IIRC, they can be remotely controlled by an operator and have loudspeakers and such for the operator to yell at people.)