Originally posted by HoutHans I see your point, but what I thought later, reflecting on this, was that - for me at least - it stopped being a painting and turned into (blobs of) paint.
It's all there, isn't it?
You watch a Canaletto painting - which is BTW very relevant on a photography forum since he often used the camera obscura - from a reasonable distance, then you zoom in and notice that everything is done in a very efficient way, with fast lines and dots, without dwelling on a single brush stroke or painting complicated shapes. It almost look like confetti.
The you watch, say, a van Gogh painting and he treats the paint almost like clay, working it in a three-D fashion, pulling it along like custard on top of a cake.
Others, like Turner but definitely not him alone, often used the back of the brush, fingers, fingernails or even their own spit to work the color
By looking at the "blobs", their shape, their thickness, the speed at which the painter put them on the canvas you can "enter his mind", find out when and where he was having a blast chuckling under his whiskers, when/where he didn't care much or at all, in which order he worked etc. etc. etc.
It's something a normal-res picture can't convey, and one of the reasons one goes to museums in the first place