Function
Which prize to draw
A module's prize stays a silhouette until every one of its tickets is earned,
so the same illustration has two states: three paints in colour, or one
silhouette colour (--prize-silhouette) that hides every detail.
The illustration is decorative — whatever it means (the prize's name, whether it is redeemed) must be said by nearby text — so it is hidden from assistive technology.
One prize from the arcade counter, drawn in colour or as a silhouette.