GNOME Photos 3.20 most notably brings non-destructive photo editing powered by GEGL for basic photo editing needs from cropping to sharpening and color adjustments. GNOME Photos supports completely non-destructing editing.
GNOME Photos 3.20 also brings a new help overlay and other improvements.
More details on the new changes of GNOME Photos 3.20 -- along with plenty of screenshots -- can be found via this blog post. GNOME 3.20 is planned for its official release on 23 March.