Did you generate a bunch all at once before starting to get some idea of what the natural variance looks like? I would think it's important to verify some level of progression over time, because with the current four it seems entirely possible that the examples could have all been generated at the same time with no changes to the model.
Aren’t they using the March 14 model like the general public? It’s frozen in time, there are no updates to it.. All of these will be drawn using the same model until they push a new update, or you switch to a different GPT But I already think they proved the point that the generation is random enough that it would be extremely difficult to track progress this way.
https://i.imgur.com/HQ1Vjp0.png
And when I ask it to draw Mona Lisa, I get this:
https://i.imgur.com/gsBU49w.png
So far as I can see, the only difference is that the GitHub repo uses the API; the ones that I have were rendered using the web chat UI. Which makes me wonder if they're using the bleeding edge model for the chat.