When the bomb tech calls 'Laser on target', it is aimed at the lower portion of the package through the bicycle's basket. This matches the X-Ray that Horatio is looking at earlier. When the water slug is fired, it shoots through the upper corner of the box.
The first necklace bomb is supposedly acetoneperoxide. This explosive does not release heat, only gas. There's no flash and no burns, only blast pressure damage.
Shadow of the camera on the robot as it rolls out of its enclosure.