That's not a bomb. That was a noisemaker at best. A bomb has a pressure wave and can do damage. 2liter soda bottles can't hold enough gas to do any damage. An ounce of gunpowder and a 6 inch iron pipe would be a bomb and it would do damage. Kill people, break windows, that would be neat.

But a soda bottle? Not even close to being a "destructive device". Well, it someone filled one with PETN or RDX or TNT or even C4 then it might qualify as a bomb. But magnesium and fluid? Hell, why not dry ice and water? Same effectiveness.