I fail to see how making these signs actually brighter with LED's as opposed to D-Cell batteries makes them any more frightening. If anything, the fact that the designers were trying to make them MORE visible (with the image of a glowing cartoon character, mind you) would lead me to believe these things weren't dangerous, if I was spotting them on my commute to work.
The difference is that the Lite-Brite is a familiar child's toy that is known to be harmless. A device using LEDs custom wired into a circuit board is an unfamiliar thing that is obviously constructed for a purpose.
By calling it a Lite-Brite, you are saying that it is a familiar child's toy. It is not. It is something else.