Feedback on cold personality at work

I am an attorney and work in a corporate office for a pretty laid-back company. We have weekly meetings where the CEO/CFO/heads of different departments are briefed by legal (myself and my supervisor). I’m the youngest person and only woman in these meetings. They tend to talk over me a lot.

On Monday I was told by my supervisor that I come across as cold, unapproachable and inattentive because I am not expressive enough. When I asked how I could improve he told me that the CEO suggested I smile and nod more often when people are speaking even if not directly to me. He also said that taking notes makes it look like I am not paying attention. I’m not sure what to do with this “advice” or how to feel about it. I feel uncomfortable and noticed today when we had our weekly meetings that the others do not smile or nod when others speak. This feedback is eating me up a little bit because I take pride in my work. Aside from this weekly meeting the majority of what I do is contract review at my desk.

I’m not sure if I should take this to heart as something to learn because I am autistic or if it is sexist “advice”. I’d like some thoughts from others.

ETA: I take advice on how to appear professional/attentive at work because I do think there is a learning curve there, it’s just this particular feedback struck me as different from others I’ve implemented.