ConstReadonlyBoth: "xy"Tiles are mirrored horizontally across columns and vertically across rows.
ReadonlyHorizontal: "x"Every other column of tiles is mirrored horizontally.
ReadonlyNone: "none"No tile is mirrored.
ReadonlyVertical: "y"Every other row of tiles is mirrored vertically.
Which of an image fill's tiles are mirrored, alternating across the fill (DrawingML
ST_TileFlipMode).