Well, in the first place a real bomb might look more like a real bomb. What exactly does a real bomb look like??
What it doesn't look like is a battery hooked to a circuit breadboard with an IC and a bunch of flashing LEDs in a star shape, and nothing else that is pertinent.
It is the flashing LEDs that clued everyone to the fact that this might be a bomb, but flashing LEDs are one thing that you would never put on a bomb because it serves no function in controlling a detonation, and further has the obvious flaw of attracting an awful lot of idiot security folks who think that anything with flashing LEDs must be a bomb.
The solution to this problem is to train security personnel into what to look for.
Furthermore, once you have decided to investigate because you have nagging but inexplicable suspicions, you quickly rule out that it might be a bomb when you discover that there are no explosives involved, which you do by having trained dogs, as well as those machines that they use to analyze swipes of objects, like your PC, to ensure that they don't carry explosives.
Once you realize that not only do LEDs not have anything to do with bombs, but having further investigated and discovered that there were no explosives, you appologize to the young lady, let her go about her business, chalk it up to experience and add it as an item for staff training.