I'm not sure if this is normal, but most of my villagers seem to have taken up healing of their own accord, and are down at the bottom of the screen healing an invisible object just below the ancient mosaic. I've attached a picture. it's wierd.

I've not had that happen unless their job choice is selected for healing. Sometimes, healers will all go to the same area that a sick person was, even after they've been healed by someone else and moved on and it takes them a bit to realize that there's no one to heal.

Once a villager learns how to heal, they should do it on their own, so that is not too unusual.

As far as the little feller on his knees, are you sure he is not just admiring the mosaic? If you clicked on him, it would have told you what he was doing.