My first cat sat upright like a human only when she sat in the living room chair. Nowhere else. None of my subsequent cats ever sat that way. Wish I had been smart enough to have taken a photo.
My lovely kitty, all 25 lbs. of him, would sit on a dinning room chair, with his front paws crossed on the table, to keep us company, as we ate dinner. He really thought that he was a human being.