At the end of June, I was on a flight from IAD and TSA at IAD pre-check had a new device that looked kind of like an old Dell computer tower. Instead of the checker looking at my boarding pass, she put the ID through a vertical slit in the machine, waited about 5 seconds for it to spit out, and waived me through. She specifically told me she didn't want to see my BP.

Anyone know what is going on here? Are they using the ID to match directly with Secure Flight data to access my flight details at the TSA checkpoint?

On my other flights since, I have not seen this device again.