Towards the bottom of the page they say: “The potential risks of misuse raise concerns regarding responsible open-sourcing of code and demos. At this time we have decided not to release code or a public demo. In future work we will explore a framework for responsible externalization that balances the value of external auditing with the risks of unrestricted open-access.”
In a nutshell they're afraid of people using prompts generating black people looking like monkeys/gorillas. And other such sensitive examples that others have posted/mentioned.
It's not about prudishness, although generating pornography is one of the concerns. In the paper there's a full page on ethical concerns, but some of issues they mention are misinformation, and perpetuating harmful cultural stereotypes around race and/or gender roles.
While I understand that view, pandora’s box is already open, by their own measurements other publicly-available technology is comparable: so the only thing they’re stopping with this is direct comparison of their tech to others.
A more cynical side of me just thinks Google is rushing out the PR (including the hand-plucked sample images) because they can see that the state of the tech is progressing rapidly and perhaps by the time their tech is release-ready a competitor will already have something better (the new round of betas certainly look promising.)
It is a little bit on brand for Google to make an announcement they have the best, only for those claims to fall over later.
