This is how you actually create a gallery and select what it will display. A secondary admin area which carries almost every setting, to be changed for each instance. Justified Image Grid comes with the tool that eliminates the need to manually write any code. The Shortcode Editor can generate it for you, according to your desired options. Even better, it analyzes existing shortcodes, changing the screen to how it looked when you created that gallery. This way you can easily edit what you've already created (or copied from this site).
In case you wish to style every grid at once, manage presets, set up sources, you need to look at the Global Settings instead.
How does the Shortcode Editor work?
The icon is found on the toolbar of your visual editor - it's always there when you need it. It's a smaller and somewhat different version of the global settings. Selected options will only apply to a single gallery.
Create new shortcodes and edit existing galleries with ease.
All settings will default to the global options or the chosen preset's values, unless changed in the Shortcode Editor.