This is what you saw

http://www.metwashairports.com/Dulles

"Dulles Diamond" Checkpoint Now Open
A new checkpoint to speed experienced adult travelers through the security screening process is now open. The checkpoint is downstairs on the Arrivals Level of the Main Terminal.

This new service will also help to reduce wait times at the Main Passenger Screening Checkpoint.

Please note the traveler criteria for using these lanes:

Expert adult traveler (2 or more trips per month)
Traveling alone
Up to one carry-on item
Security ready (3-1-1 for liquids/gels, laptops out of the case, shoes off)
Families, passengers traveling with children, pets, and other passengers with special needs should use the Main Passenger Screening Checkpoint on the ticketing level of the Main Terminal. Employees, including Flight Crew, must continue to use the Employee Screening Checkpoint.