The left pane has the drawing tools which include several shapes. One, in particular, is called the Symmetry tool, which “mirrors” a shape’s stroke, creating a symmetric pattern.
Besides tweaking images, I find Sumopaint to be useful in creating simple logos using the text and brush tools.
Other than the ads that appear on both sides of the web editor and intermittently crash Chrome (the tool uses Flash to run the web version), this photo editor gets the job done easily and is more than suitable for users who are not photo editing experts.