Once an image is opened on your Macintosh, the system can read the metadata, if there is any. AttachedThis has been possible for years and years, but as more and more people have started using Adobe export for web option in their image processing software many image files are stripped of all but the most basic data.
For example,
last night while responding to this thread on my iMac I looked at several image files, and most of them had been stripped of all but rudimentary metadata. My own files on the other hand,had a complete list of meta data easily visible using the Macintosh system level EXIF capability,which had a huge amount of data, including my own personal copyright information ,the camera used, the lens opening used,the time digitized, The body serial number, the tone curve, and many other things.