What Do All the Icons Do When I Click Custom Page?

Choosing the gear icon opens up a modal where you can configure the title, change the item being displayed, or change the style settings. These may vary depending on what type of pane this is. A pane coming from Views may allow you to change the title of the pane, the number of items and fields displayed, or what style is being used. Previewing changes is also quick and easy from the gear modal.

The paintbrush icon also uses a modal. This one allows you to change the style settings for the pane - Panopoly only comes with one style, but this can be expanded by the use of additional style plugins, which can be written and added later as necessary.

The Trash can icon opens up a dialog box for confirmation on deleting the pane. Your choice, choose wisely!

On the right side is a grab handle (the cross with arrows). Drupal uses grab handles in many places to ‘pick up’ an item and move it from one place to another. By using the grab handle, you can drag your panes from one panel region to another, or rearrange the panes in your current region.