just like cameras the screening machines have exposure levels too, standard exposure level help resolve details of every day items, shielded items or items with a high density of metal need a higher exposure rating to help resolve the details inside of the item (save for taking a hammer to it), it would appear iPad has minimal shielding and components with low metallic density, (they were able to resolve the details of the components inside the iPad at default setting)
on a side note
"dameon51 :
It doesn't have a CPU, it has a hamster on a wheel."
that would be a Chinese hamster right, cause they cheaper....