done by the folding of the dog's face. Human perception is way too easilty tricked. However, isn't there something in that. I mean, how can we, observe something and recognize that what we are observing is not real? how can we differentiate between our own faulty perceptions and that which is reality? is it because we have other senses that do not agree? how can we then say that our touch preceeds our vision? is it that when we look closer it changes? how do we know that one point of view is more dominant than the other?
Experience. We know from experience that when it comes to the shapes of objects, touch is more reliable than vision. This experience comes from optical illusions and playing with things and stumbling around in the dark.
We also know from experience that paper things don't follow us, so we realize that there is something else at work. This is why babies think that if they cover their eyes you go away; they don't have the experience to tell them that you're still there, waiting for them to open their mouths so you can stuff them with strained peas.
Also, the video works better than real life because it doesn't allow us to use our depth perception to figure out the real shape of the dragon's face.