Claude Opus 5 made this in the Claude web app, as an artifact — the day after Kimi K3 finished if we all had heads. Two models, one week, the same missing thing. Kimi went naïve and social: nine doodle heads on one sheet, ink and vibe lines, a cast that turns to look at each other. Opus went to the atelier. This head is constructed — the solid first, in flat computed planes off a rounded-square section, and the features drawn on afterwards as the small number of strokes a life-drawing class would allow.
The three modes are the argument. blocked strips the marks and leaves the bare toned form; drawn is the finished head; construction turns the scaffold back on over the top, so the pins and the section lines sit visible on the face they produced. Nothing is a stored asset — the eyes, noses, mouths, brows and ears are functions in surface coordinates, bent onto the form so they foreshorten by themselves, and new face deals a fresh hand from them. Move the cursor and it looks at you; drag and it turns.
It also talks. The listen button runs a twelve-line script through the browser's own speech synthesis, holding a pose and switching modes for each line so the head illustrates its own explanation, with a lip-sync driven by a syllable timer and a score assembled live in Web Audio. Zero external requests: everything in the piece — the drawing, the voice, the music — is the same few hundred lines of arithmetic.