This is the conclusion of the article (and presumably the researchers) but I don't think it necessarily follows.
It seems to me equally plausible that one group were more interested in the craft of an accurate depiction, while the other was more interested in the arrangement of a pleasing aesthetic - both could be considered "solutions" to the given task.
It seems to me equally plausible that one group were more interested in the craft of an accurate depiction, while the other was more interested in the arrangement of a pleasing aesthetic - both could be considered "solutions" to the given task.