Perhaps that's another symptom of dementia, Cozie and Lion? My mum couldn't read people's faces either, so she couldn't interpret any emotion on my face except anger, happiness or extreme sadness. Anything else - irritation, embarrassment, confusion, awkwardness, etc. - was beyond her. She also had an inability to empathise. If she wanted something, she wanted it NOW. If I was upset about something, she would turn to conversation to herself.
Maybe Trump is just a narcissist. I'm hoping his family is looking after him.