She compares the pieces to confirm they have the same silhouette. She copies the designs onto the new pane and mixes a matt paint that matches the one on the broken pane.
She then shades the designs on the new pane with the matt paint. She dabs it with a brush to create fine criss-crossed lines. Then she switches to a brush with shorter and stiffer bristles. She removes some of the paint following the designs on the pane. This creates highlights.