Image Library UI has a toolbar with commands and tree list of images, organized into categories.
Toolbar has the following commands:
Add Image from file opens up separate dialog:
"Resize selected images" command allows you to resize images that have width in pixels more than selected value. This is useful when you have captured a bunch of screenshots that do not fit browser or PDF page width.
"New blank image" allows you to create an image with user defined size and filled with selected color. Using it and annotations you can create diagrams like this:
"Cloned" images are explained in detail in this topic: "Cloned Images"