All because they want to keep you secure.
As part of the DMV's effort to develop super-secure driver's licenses and foolproof identification cards, the agency has issued a smile ban, directing customers to adopt a "neutral expression" in their portraits, thereby extinguishing whatever happiness comes with finally hearing one's number called.
...DMV officials say the smile ban is for a good cause. The agency would like to develop a facial recognition system that could compare customers' photographs over time to prevent fraud and identity theft. "The technology works best when the images are similar," said DMV spokeswoman Pam Goheen. "To prepare for the possibility of future security enhancements, we're asking customers to maintain a neutral expression."
Also note that the "new software is programmed to reject attempts at exuberance or human warmth" and it sends "an error message if it detects a non-neutral expression."