What did Sunny do to Joachim's pictures? How did Joachim feel about that?

Sunny brushed his tail against some of Joachim’s oil paintings that were still drying and smeared parts of them. When Max saw the damage that the dog had done, he braced himself for a tirade from Joachim. But to his surprise, Joachim liked the feathering effect created by Sunny’s tail. In fact, he planned to try to duplicate the technique.