it may just have resulted from the development in skills and craft from coarse in the begin times to the refined stages it reached later on

Yes, probably so. Heidegger talks about techne in his Die Frage nach der Technik (The Question Concerning Technology). In his Der Ursprung des Kunstwerkes (The Origin of the Work of Art ), which is worth reading, he discusses van Gogh's painting of a pair of peasant boots.

Ceci n'est pas un seing.