The author of the article clearly doesn't get it. They say "8- to 12-year-old children evaluate harms more severely when they are directed toward more attractive animals." and then tries to explain that with "beauty is pleasurable". Sorry, it has nothing to do with that.

We are genetically conditioned to be attracted to beauty, to equal beauty with health, and good genes. We choose beautiful mates in effort to maximize our children's chances of survival. The fact that we also like pretty animals, and everything else described in the article, is just a side effect of that.