We went to Museo Prado and I was disappointed that no photos were allowed. But why was l disappointed? The best I could have done was copy somebody else's art.
At a number of spots in the museum, however, individuals sat at easels with their oil paints attempting to do just that: copy somebody else's art. That apparently was allowed. But how does it differ from taking a photograph?
For one thing painting takes talent. Capturing a 2D image of 2D art with a camera takes very little talent.
Intent might also be a factor. One motivation for painting a copy of a masterpiece is to study how the original master captured the 3d world in a 2D medium. The intent in photographing a painting might be to avoid having to buy a print at the museum gift shop.
But as much as I might understand the rules against taking photos, I felt a desire to bring home something of the images (other than my memories). So I sat down and sketched several pieces. I would like to say that the selection was based on what spoke to me, but it was often whichever piece had a bench in front of it.