While completing a relentless set of errands for his
master's wife, Taddeo (in the background) stops to
admire a painted palace facade. On returning he
is put back to work grinding pigments, but—imagining the facade—he draws the scene from
memory with a twig in the powdered paint colors.
To make it clear that each of the figures in the drawing
is Taddeo, Federico has inscribed his brother's
name on his tunic.