This is a picture of a real suitcase bomb. I don't think there was an innocent reason for the kid's design. It was purposeful and that purpose is evident today as the family has met with their lawyer.
If I were the government, I'd be looking at the alarm function and programmability and whether there were screw terminals installed at the alarm output intending connection to something else.
With today's electronics miniaturization and vast simplification of display drivers and the basic clock/time derivation functions, this “hobby project” is grossly mismatched. It is an exercise in design, layout, wiring harness expertise. In other words this is a precursor bomb that is intended for training, and for dry run or just Islamophobia provocation.
Real suitcase bomb bookmark