I think I see the disconnect. "Practical application" here does not mean "doing a scan". Don't let the word "bit" lure you into thinking we want to do something on a computer. This is using bits purely as a unit of measurement of information quantity. It applies practically in reality the same way any other unit of measurement applies. The same way we can ask how much something weighs or how fast it's going, we can ask how much information it has.