This little one acts completely feral unless you make the "mommy greeting kittens" noise at them. When my phone isn't making them unsure they will come charging to the front of the cage for attention by the second trill.
You can see the body language change in the ears with the first and second trill real well
In case anyone was wondering, it looks like the human is working on socializing the kitten. This is often done at shelters when a cat or kitten hasn’t been around humans enough, has had too many bad experiences with humans, or just has been around a select few humans exclusively.
The point in this is to (1) make caring for the cats easier, (2) help the cats get more comfortable with their surroundings (humans are everywhere, always, forever), and (3) it helps the, be more adoptable, meaning they're less likely to be stuck in a shelter for the rest of their lives.
Edit: How did I not realize there was text above the video?

















