Plagiarism and the desire to share

Finnish media reports that Kristina Isola, a designer at Marimekko has apologized for plagiarizing a painting by Maria Primachenko in her print Metsänväki (“Forest Dwellers”). Plagiarism is not that newsworthy but her motivation caught my eye:

“I didn’t think about copyright or that I appropriated someone else’s creative work. “Forest folk” felt so close to me and I wanted to share that forest feeling with as many people as possible,”

The desire to share objects of beauty is probably one of the causes that drives most of Pinterest. This doesn’t diminish the charges of plagiarism or copyright violation but at what point does the desire to share beauty become socially/legally wrong?