This is the option to use to do manual changes to your design, like using the drawing tools to change or paint stitch symbols from the palette or manually changing values in the options column. Once you have done any operations they can be moved on the canvas with the OffsetX (left or right)and OffsetY (up or down), using the little arrows to set numeric values.
It can also be activated by clicking on this symbol from the top left toolbox: