Though I agree with the point that paper makes (it makes a good case that the little square mental model of a pixel is mostly inappropriate) it does seem focused on imaging and does not mention places where the little square mental model is appropriate.
Pictures of cats, subpixel rendered text, or company logo SVGs as displayed on a web page are point samples and not little squares.
User interfaces are good examples of often being little squares. Calling HN's beige background a point sampled discrete representation of an underlying continuous function seems pretty tortured — to me it seems like a bunch of beige little squares.
