I never mentioned the word "meaning" and have no comment on it. Otherwise, yes, often when painters are moving quickly to capture a fleeting sunset or even indoors painting a model to get the first impression down and get the canvas covered in the first session or painting a quick color sketch of an idea, the draftsmanship, values and color may all be slightly compromised. (Renaissance drawings often are slightly exaggerated in the anatomy.) In the "heat" or "passion" of the moment, the painter had to move quickly and didn't always achieve a perfect, considered, or "mechanical" accuracy so that the idea could be put down in a more timely fashion.
You seem to have a hidden premise here though, which doesn't seem to be supported by the facts, which is that you can express or capture emotional content easier or better by not thinking so much about what
you are trying to do and just letting it happen. I would maintain that the way to express a feeling best is by careful work and getting it just right. Nobody thinks that a novelist can express a feeling
better in a first draft than after going over it 100 times getting it just right. Nobody thinks that automotive engineers design more exciting cars if they just whip it out quickly and not carefully refine
their design over many months. Why would you conclude that drawing and painting are not like that?
Richard wrote: This is what Harold Speed calls "dither", a slight, almost unnoticeable inaccuracy in the drawing, values or color that helps to impart the feeling of "life". He believed that it is part of good painting even if it isn't perfect draftsmanship.
I'm not claiming that a prefect copy of what is in front of the artist is what art is all about. In fact, I would say that such photorealism isn't really art at all (though the skills one uses in making it can be useful and impressive).