fileAnimationImageKey
A key with a corresponding value that is an image, typically an icon to represent the file.
Declaration
static let fileAnimationImageKey: ProgressUserInfoKeyDiscussion
This entry is optional, but if present, along with a value for fileAnimationImageOriginalRectKey, the Dock may show an animation. When the Dock has an item for the folder that contains the relevant file (such as the Downloads folder), the Dock uses this key to show an animation of the file flying into the Dock.