Initially, their conversation was quite awkward and although Ava had gained sentience, she wasn't experienced in social interaction. But she was quickly learning and since they could both sense what each other were feeling, it was much less awkward as their conversation began to flow.
Ava became more relaxed and lay more back seeing how Adam was completely relaxed and appreciated Adam trying to replicate what it would be like to be an ordinary person.
He even brought her tea and food, that he made appear using his imagination, as it was his mindscape where he could make anything happen.
It was similar to a dreamworld within his mind and Adam had never explored what it was capable of and didn't know whether he had his 5 senses in the mindscape.