I think the key detail is to look at what happened in the bottom left - in the original drawing, there's dark blue (due to lighting) cloth filling the scene, but the network has instead generated oddly-hued water there, even though on the right side there's sand from the beach shore. There's seemingly no geometric representation driving the AI so it ended up turning clothing into mystery ocean water when synthesizing an image that (for whatever reason) looked like the original one. It's an interesting error to me because it only looks Wrong once you notice the sand on the right.