Image Widget (fig. 1)
When in Editor, select the target Image Widget, open the Style tab and expand OoohBoi Image Mask panel. Upload the mask image (should be SVG file type!) and play with options.
Background Overlay (fig. 2)
Select the target Section or Column, open the Style tab and expand Background Overlay panel. All the Image Mask options will be available under the default Background Overlay panel options. Upload the mask image (should be SVG file type!) and play with options.