The AAE sidecar format present in the iOS 8 and later and Mac OS X Yosemite photo handling for transfer of non-destructive adjustments between systems and apps. The AAE file is an XML based format with various elements with adjustment in their names. The primary element is the data element stored as Base64 binary.
It seems to contain some information based non-destructive adjustments in photo editing. They are primarily used to preserve editing changes. They can appear for unusual changes in your picture settings.