If you create a symmetrical copy of a piece, the effect is to link the two pieces so that edit actions done on one piece are automatically done on the other. In addition, stitching to or from one piece is automatically done on the other.
To create a symmetrical copy of a piece:
On the Main toolbar, click Select.
On the Horizontal contextual menu, ensure Pieces is selected.
In the 2D window, click the piece you want to copy.
Go to the Context view, in the Actions section, at Symmetry.
Do one of the following:
Click X to have a symmetrical copy of the piece created, with the grain line following the X axis.
Click , then Y to have a symmetrical copy of the piece created, with the grain line following the Y axis.
The new piece is displayed in the 2D window on top of the piece that was copied.