Cleaning a photo by re-encoding it
The tool decodes your image, redraws it on a canvas and saves a new file, which leaves the metadata behind.
Nothing is selected or edited tag by tag. The method is deliberate re-encoding: the new file is built only from pixels, so location, camera model, timestamps, editing software and author or copyright fields are not written into it. That is the mechanism, and it also means a few side effects, listed below.