Yes, this is *exactly* it. 100%. Again, it took me about 10 or 15 seconds to figure out where exactly the racket was coming from, and by the time I did they had already formed their line. Perhaps they were 100% professional from the time they began, but once the line was formed and anyone/everyone was prevented from getting through, they were just standing there, waiting for someone to say "and...that's a wrap," and let them get back to what they were doing before. That's when I noticed the fact that they didn't have stony faces of seriousness.

One of them was even gesturing in a friendly/somewhat joking manner to a friend trapped on my side of the line. Once everyone knew what was going on it was OK, but anyone who had heard what sounded like a herd of elephants simultaneously running and then stopping, had stopped in their tracks and just stared.

As an afterthought, I just remembered now that I saw some guards on the other side (not the "secure" side I was on), holding up their hands in a motion to stop anyone else from entering the x-ray area. I wish I'd thought to look at the people who had their shoes off and/or were putting their stuff on the belts at the time. If I was that startled on my side, I'd hazard a guess that they were extremely scared. To me, it's a high-pressure situation, going through that thing; being separated from all your possessions; hoping you don't beep and/or get pulled aside for further examination. Imagine doing all that and being stuck in the exact middle of a "red rover" type lockdown. Guess I was lucky not to be five minutes behind schedule yesterday...