KvadrantCheckBox

The phone's check box, from its own System.Windows theme rather than from the shape language.

Three things it does that a reconstruction gets wrong. The box is 32 px square with the same 3 px border everything else uses. Its background stays transparent when checked — what appears is the tick, in the foreground colour; held down it fills with KvadrantColors.checkBoxPressed, which is white in the dark theme and transparent in the light one — not the accent, whatever the token's name suggested. And the tick is a filled path, not two strokes: M0,123 L39,93 L124,164 L256,18 L295,49 L124,240, stretched to 23×21, which is why its two arms have different weights and why a pair of straight lines never looks quite like it.