I don't think its any different than any other time we see something we like and instead of buying it, we say "I can that myself!". If someone doesn't want their work imitated than they shouldn't post pictures online. Most people I know would be flattered and happy they inspired someone else. I do think it's different,both ethically and maybe even legally, to copy someone's work and post it for sale on etsy or state mass producing. But for yourself? Totally ok.