One of the new features in macOS Mojave and iOS 12 is something called Continuity Camera. It lets users right click in a macOS document and insert a new photo from an iOS device. As soon as the new photo is taken, it appears in the document, without having to first be saved or imported. FileMaker Go supports similar behavior with image container fields, but this behavior does not currently extend to FileMaker Pro Advanced.
Apple has an excellent support document describing the feature.