Some DHS employees told some people with an infant's passport that the passport with the photo of a smiling baby is not acceptable ID because smiling isn't allowed in passport photos but that they'll let it pass those times but they should get a new passport.
If DHS employees weren't so serious in those kind of comments, then it would have been something else. But the DHS employees were serious -- even as infants aren't required to show ID to be processed at the TSA screening checkpoint, even as passport photos for infants are allowed more official latitude by issuing authorities than passport photos for older minors and adults.
It's almost like someone had told DHS employees about how to try to detect "fake passports" or something like that and recalled that smiling photos aren't allowed since it doesn't show a "neutral expression" or something like that. So much for completed education.