Unless of course you have access to modern technology, then you can also use an x-ray machine, a cat scanner, and an infra-red machine. Those devices are quite reliable these days in telling you what's in the box without having to open it.

yes, and a healthy discussion of the images, which are always open to interpretation should be always welcome. Something like when you post images of seismic surveys. People look for trends, lines, saddle shapes, traps. On surface they are just wiggley lines that mean little without discussion, unless of course, some decide what they are, then tell everybody what the party line is and then close the case to any further discussion.

db