When you paint an object or person, you can no longer take its lines and curves and colors for granted. Neither can you see it as an isolated thing. Its surroundings touch it and reflect colors and shadows on it. You have to see that it exists in a context, and that context is continuous.
When photography was invented painting became less useful, it wasn’t the only way to record an image. Photos record the reality of a moment, so that even when that moment is gone we can look into it with minimal outside interpretation. Even if the photographer doesn’t see something, if its in the frame, its there forever.
Painting, though, is a totally different beast. Its not a captured instant but the result of a scene in four dimensions being processed through the artist’s senses and then compacted onto a two dimensional canvas. Light, color, weight of an object, how it arranges into its surroundings, and all the tiny changes that happen to these variables in the timeframe of the painting process, are all summarized into the scene.
The artist is working from many moments in time for many hours put together. Maybe rather than a photograph, a painting might be more relatable to a video, although of a generally still scene. On the other hand all that indirect processing makes a painting much more subjective. This adds on another dimension, of consciousness, when the painter’s mind and hand interacts with the scene.
While I’ve mainly been talking about realism, which I love, there are so many types and styles and lots to say about all of them for sure.