There are two separate scanners at the airport. The microwave scanners that they cook, I mean scan, us with personally. They see your skin and if you have anything under your clothes other than skin.
“Early scanners were a bit too revealing. Nasty TSA agents were taking phone pictures and passing them around – so they made the displays less, uh, true to reality.”
Next you have the carry on baggage scanner that x rays your checked bags and laptops and other articles.
“Who is this person?”
The X-ray machine can see through anything except thick enough metal which comes through as black. If they cannot identify a thing they are supposed to have you pull it out and have a look see. Of course with lines always backed up, they do this sparingly because almost none of us are terrorists. Close enough to zero as to be zero. Still we all gotta pay our TSA 22 dollar please violate my personal space fee to ensure we are not terrorists.
Yes, they can see through your pill bottle. Unless its made of lead. Then they can’t. They will ask you why you have a lead pill bottle though. Maybe. It might just coast on through.