Connecting it's capabilities to simulating the recreation of such paintings... that's I suppose interesting. But adding brush strokes to produce an image is probably well covered by video footage in its training data. e.g. all the Bob Ross videos in existence.
For example I can watch all bob Ross videos 300 times and never paint a thing and this action would not teach me how to paint.
They have been generalizing for a long time, but spacial 2d and 3d art through tool use is a very engaging way to show it. It is harder for people to deny generalization.
Now Opus 5.5 clearly has had some sort of visual arts training, the step function change in ability implies that to me, but it can apply its spacial artistic reasoning to pretty arbitrary tools.