Clipping (Or Masking) A Bitmap
By default, an imported bitmap (such as a photo) is an <image> element which is not editable by a node tool.
To Work around this, convert the image into a rectangle with pattern fill. Click On Edit Then Click On Tile (You can also use the keyboard shortcut Alt+I)
Before Tiling, The imported Image Will Have Handles Like This.
After Tiling, The imported Image Will Have Handles Like This.
The Image is now "editable" Dragging the new handles with the mouse will alter the shape and form of the imported image. (Notice the curved corners?) Try this out, experiment, see what tile can do.