I can tell you that last year at the airport I was asked if I wanted the full body or the pat down and I thought I'd try to full body scan. I honestly didn't even think about it and yes I'm a wearer. The machine spun around and the person said I could go so nothing was mentioned. I did look at the person after me and it looked like at the top of the machine there were green LED things that would I guess set off alarms should they be hiding something.
This leads me to believe it will detect objects but maybe lace and some hair doesn't set the machine off.