Well I can tell you what my father-in-law felt when I created a painting from the photograph that he took of a pair of parrots: delight, pride, pleasure, happiness, gratitude, etc. I gave it to them as a gift - so I didn't even ask permission beforehand as it was to be a surprise.
Then, on the other side of the coin, a friend of mine has just had her book plagiarised for the second time - and she's livid.