I don't understand how the item matching is working. Do they have textual descriptions of each item (including colors and patterns), or are they somehow building vectors for the images and then doing cross-modal vector calculations?

If it's the first option, then generating those descriptions seems and important thing to mention.

If it's the second, then it's a pretty significant result! I've seen some papers that indicate some possibilities in that area, but never anything working as well as this.