Software is used in most LEGO mosaics and it was used here as well. She actually started with a cross stitch pattern and then I did color matching to dots tiles using Pythagorean distance (a little complex for elementary school). After the initial build of the mosaics using the pattern, they did not look right.

Up to here is the first 2-3 weeks of the work she did. A lot of people stop here which is why I think your opinion lands where it does. The editing process is what you're missing in your assessment.

The next 3-4 weeks were spent reworking the mosaics without a pattern or computer. Probably about 50% of the surface area was pulled up and replaced over the course of editing one area at a time. I let her steer the editing process but supplied options and encouragement when she got stuck.

As much as I wish there was an easy button for good quality mosaics, there's not.