OK, I'll cop to that. Hollywood conditioning it is. Nevertheless, these devices were designed to play into what the public is looking for in a bomb. That is what makes them an effective advertising device.
If you pull such stunts, the state is going to be very, very angry with you. As well they should be.
Looks like you did, semi-concurrently to my post.
I have to disagree with you on that position, too. Besides IED briefings, I've also seen lots of bombs in Hollywood movies, and I think I know what the average, reasonable person's idea of a bomb looks like. Even if we move past the idea of the LED timer that beeps every second, there has to be some kind of mass to an explosive device. Everyone knows what a pipe bomb looks like. Lots of people have seen more sophisticated and dangerous bombs portrayed in movies -- dramatizations of the WTC and OKC bombs, or similar bombs in the X-Files movie, Fight Club, or Sleeper Cell. All of the above have a great deal more mass than the ATHF devices.
I think a reasonable person might be curious, even cautious, about these devices -- even so far as to ask an authority to investigate it. But it should've ended there. I think the bomb squad that detonated the first device did so purely out of boredom, looking for an excuse to put their training into use and blow something up.
Also, from the footage I've seen, these signs are most visible -- and most effective -- seen at night. In the dark, the illuminated character is visible, and the "frightening" bits and pieces are not. The creator did not intend the devices' bomb-like nature (which I still contest) to be effective, but the appearance of an illuminated character in the dark.