Different ways of laying out the image in the background of the block.
Enumeration Members
Fill
Fill: "fill";
The image retains its original aspect ratio, and is as small as possible while still completely covering the block
Fit
Fit: "fit";
The image retains its original aspect ratio, and is as large as possible while still fitting in the block
Original
Original: "original";
The image is shown in its original size if possible
Stretch
Stretch: "stretch";
The image is stretched to the bounding box of the block
Tile
Tile: "tile";
The image is tiled in its original size vertically and horizontally to fully cover the block