What does the "Empty srcset[]" breakpoint in Picture Module? I'm using the Picture Module. 

What does the Empty srcset [] breakpoint exactly do? Why should I use it, and why shouldn't I use?
The empty srcset is to be used when there is a breakpoint where you don't want to display your image. An example might be where the image in question, or a parent div, is display:none in the css. The image would normally be downloaded anyway, but by having an empty srcset at that breakpoint, no images will be downloaded.