AAE sidecar format
The AAE sidecar format has been reported as present in iOS 8 and OS X Yosemite for transfer of non-destructive adjustments in photo editing between systems and apps. It is an XML based format with various elements with "adjustment" in their names. The .aae file accompanies the actual image which can be a .jpg, .heic or any other file allowed in the iOS photo album. The introduction of this file format seems to have been done with little commentary and no online documentation.
On importing edited pictures from an iOS device into a Windows system, it appears only the JPEG file gets transferred, losing the edits (the picture appears in its original unedited form). Looking at the raw contents of the iOS data from Windows (going to "My Computer" and then the particular device) finds some mysterious "Local Disk" items alongside the graphics, which Windows refuses to open, move, or delete. These are perhaps the sidecar files, represented in the filesystem in a way that Windows can't handle.
AAE XML structure includes plist, dict, key, data, date, and string tags.