IMHO, maybe the M4 carried by regular Army uniformed officer is a borrowed one from an SSG dude just for photoshoot. But his casual looks hint towards that he could be an SSG himself.Are these M4's?
Do regulars use M4's now?
Or perhaps thats an SSG guy in Army Uniform as he removed identification patches from his shoulders. Maybe he likes the Army uniform camo pattern a lot and SSGs have acquired those camo uniforms in limited quantities as they tend to blend well in urban, suburban environments as compared to old style woodland camo