No, it’s two screenshots from Anthropic documentation, stitched together: https://platform.claude.com/docs/en/build-with-claude/prompt...
The post even links to that page, although there’s a typo in the link.
Author here: I have just fixed the typo. Thank you.
And yes, these are screenshots from Anthropic’s documentation.
They're not even stitched together ; there's just no padding between the two images.