First of all, the Guardian is known to be heavily biased again Musk. They always try hard to make everything about him sound as negative as possible. Second, last time I tried, Grok even refused to create pictures of naked adults. I just tried again and this is still the case:
https://x.com/i/grok/share/1cd2a181583f473f811c0d58996232ab
The claim that they released a tool with "seemingly no guardrailes" is therefore clearly false. I think what instead has happened here is that some people found a hack to circumvent some of those guardrails via something like a jailbreak.