The video equivalent of a book is any imaging screen. Cathode ray tube, LCD, whatever. That's not inherently bad. The social construct of mass one-way transmission coming in through an imaging screen and paid for with advertising, which is ultimately designed to modify your child's thinking, is not healthy in the context of the standard biopsychosocial model of disease. We didn't evolve to handle professional psychological manipulation by the age of two. If we had, then it would be healthy. But we didn't. So it's unhealthy.