When a chatbot draws a picture for you, the usual experience is a pause followed by a finished image dropping into the conversation. Simon Willison, writing about a chat tool he has been working on, pointed out a detail that changes that rhythm: the tool can spot an image being written out and start drawing it before it is finished.

"One fun detail is that it notices SVG images that are being generated and progressively renders them in the chat while the tokens are still streaming in."

To unpack that: most chatbots generate their answers as a stream — the text appears word by word rather than all at once. Those words are produced as small units called tokens, and an image made in SVG format is, under the hood, just a special kind of text: a set of instructions describing shapes, lines and colours. Because an SVG is text, it can be streamed like any other answer. What Willison describes is a tool that watches that stream, recognises that what is being generated is an SVG image, and renders it on screen progressively — so the picture assembles itself in front of you as each new chunk of instruction arrives, instead of appearing fully formed at the end.

This is a detail about how the tool feels, not what it can do. The finished image is the same either way; what changes is the experience of waiting for it. Watching a drawing take shape in real time makes the interaction feel immediate and alive — closer to watching someone sketch than to being handed a printout. It is a small piece of interface polish, and Willison himself flags it as that: a fun detail, not a headline feature.

Who is this for? Mostly the kind of person who enjoys following the mechanics of AI tools for their own sake — the texture of how they work, not just what they produce. If you find the real-time, visibly-generating quality of chatbots part of the appeal, this is a thoughtful touch you will appreciate. If you only care about the final image, it changes nothing for you.

There is also an honest limit worth naming: the audience that benefits most directly is the people building chat interfaces. Progressive SVG rendering is a technique other tool-makers can copy, and Willison's note functions partly as a pointer to how it is done. As a user, you do not configure or enable anything — you either use a tool that does this or you do not. And the benefit is aesthetic; a progressively rendered image that turns out badly is still a bad image, just one you watched arrive.

On availability: this is not a proposal or a demo of something hypothetical. Willison describes it as behaviour the tool already has — it is shipping. Whether you will encounter it depends on which chat tool you use, since this is a feature of the interface rather than of the underlying model. But as a small, concrete example of how the feel of AI tools is still being actively designed — not just their capabilities — it is a telling one.