Fullscreen preview undiscoverable
The full screen functionality of the image viewer is difficult to find. The button is not described in any way (no tooltip or description), and arrows suggest something to do with movement (panning?). This is compounded by the fact that there's no discoverable way to exit this mode, apart from exiting the application.
Fractal git revision 4383ad80, Fedora 27, KDE/kwin 5.12.