Seeing it in print in a book or on a web site might elicit an impression. It is well painted and detailed, after all, but seeing it in real life hanging on the wall of the art museum is breath taking, and it is smaller than a post card. As a matter of fact, it is because it is so small that it is so compelling and awe inspiring. It is yet another proof for the argument of authenticity and works of art. Proximity in real shared space and examination of the physical reality of the work and its sense of age (it is nearly 500 years old) causes a viewer to pause, examine and be dumbfounded.
The argument of authenticity gets into definition of the word "knowing". Millions of people would claim to "know" countless works of art from seeing images in books and on television and via the Internet, but it is generally agreed that a person only really knows and understands a work of art when they have seen it in proximity and even more acutely if they have had physical proximity and / or contact with the work of art. A painter working in oils may understand Leonardo's Mona Lisa, a visitor to the Louvre can claim to see the painting, but a curator, scholar or conservator who has been near the painting and touched it knows it even more fully.
Until I was out of high school our house lacked books. There were libraries that I could go to and books were expensive. We had a set of World Book encyclopedias from 1947 and my mother gathered Reader's Digest Condensed and abbreviated books because she had a subscription to the magazine. The lion of Lucerne seemed to stand out in those World Book books, with only black and white photos, and few of those, it seemed like the lion was in every book. I can understand why the sculpture would resonant with a post-war audience and editors. My memories may exaggerate how many times the image appeared in those books. But, see it as often as I did as a child I did not know it as I do now from having visited it.
Thus we have two works of art that I have a claim of "knowing" enhanced by actually traveling to places and being in close proximity to the works and seeing scale. In the case of the lion, it exists in its original context, but in the case of van der Weyden's painting that piece of art is no longer in Europe and has a new context within the 20th Century construction of The National Gallery of Art. The neo-classical setting, the walls of the gallery and the nearness of other comparative works of art give St. George and the dragon a new context, new but still authentic in being an authentic museum in the context of a capitol city.
Reims cathedral is not the only Gothic cathedral that I have visited, but like all cathedrals Reims has its own unique elements. We could discuss the authenticity of visiting a cathedral as opposed to seeing one in a book or in a motion picture. Scale, presence, atmosphere, the context of the city itself, all those things and more are aspects of authenticity. I had first noticed Melchizedek and Abraham in my art history textbook in college. I might have assumed that they were stone and approximately life size.
But... they are not life size. The figures are approximately half of human scale and stand in carved niches above eye level. That, along with the color of the stone and its color and texture within the cathedral all make for a sense of awareness and a profound feeling of having "met" the art. My thoughts and feelings have been changed after 39 years, my awareness has been changed, by actually seeing the art.
On the outside, at the entrance portals, the sculptures of Reims are larger than life. Created over centuries by more than one artist, I have taught about those sculptures for years, but being near them is different. And even in proximity it is difficult to convey the effect of their size. The marvel of them is that as big as they are they still seem intimate. It takes a photograph to remind me that the comfortable and inviting herald angel is really a giant of stone. One also becomes aware of a history of suffering -- the martyrs of Reims and the destruction of World War I, by being there physically and seeing damage and having a sense of awareness and resilience.
While traveling and touring, one's eyes can explore more than is captured by a photo on a page. At Schloss Heidelberg my eye could roam over the facade and find details.
Exploring and examining only by books and via the Internet, I would be dependent on the photographer's eye and the scholar's words, just as you are while you read this. But in the presence of the architecture and sculptures I can see and select. Thus I noticed Herakles / Hercules.
He is easy to spot with his lion head and lion skin. Herakles' Greek physique and the scallop shell above him are visual clues to dating this without the aid of literature or guide. But would I find this if I wasn't there? And does my sense of knowing it in the stark brightness under a vivid blue sky on a summer day high above Heidelberg after wandering the alt strasse of the old university make my sense of it different than it would be from a book?
It isn't only artworks that demand authenticity, it is their subjects as well. Who has studied Sturm und Drang and Romantic landscapes and not seen turbulent waterfalls, floods in the Alps, and sensed the terror and power of the torrent and the Deluge?
Standing near the Rhine Falls, in the noise and spray, one is impressed and awed. I can see why painters would try to convey its force and terror and calamity as well as its wonder and beauty. In that case the questions of art and authenticity take on new dimensions, ones about conveyance and expression and an illustration versus a physical experience. In that case, as perhaps with all art, at least with mimetic and figurative works, one confronts and examines "vision".
This can only be done by travel. To leave the environment of home or classroom and venture to other places is the only way to really "know" art and scenic wonders.