That could also be human training as well. For example, an artist’s work would be used as a “correct” sample, and the machine told to make some other image based on the correct samples, and people would mark results with those tags.

Last day of school in elementary the teacher would often give us back stuff that we made through the year and sometimes classroom stuff that would have gotten tossed over the break, our backpacks were never more full than the last day of school.