As a blind person this was quite difficult to read (emotionally). I don't have any additional mental needs, but for obvious reasons I'm unable to read other peoples' visual body language, maintain eye contact or gauge their facial expressions. And because I can't do those things, and have never been able to do those things, they don't always come naturally to me either. I have a habbit of appearing to have a very serious expression on my face when actually I feel quite light and carefree, for instance. Maybe great in a poker game, I don't know.
As an example of this, I never learned to nod or shake my head in response to questions until a recent trip to visit my partner in Mexico. Her sister is hearing-impaired, and so gestures like those were often the simplest way to communicate meaning. My partner, who is also blind, has grown up using those gestures because of her sister, but for me it was like learning something new.