Person First Language and Dehumanization

If you're not familiar with person first language, it is basically an attempt to speak with a grammatical structure that literally puts the person first. I was first introduced to the idea by a professor of special education in college, so I'm going to give you examples related to that topic. Non-person-first language: autistic child, blind man, downs kids. Person-first language: child with autism, man who is blind, kids who have down syndrome.

What's the difference?