A content author is using the Experience Fragment Core Component to select from the existing...

The Configure Dialog in AEM is used for defining properties specific to the instance of a component placed on a page. For the Experience Fragment Core Component, authors use the Configure Dialog to:

Define Properties:

The Configure Dialog allows authors to set various properties for the selected experience fragment variation. This includes selecting the specific variation, adjusting settings relevant to the variation, and setting other configuration properties that define how the fragment should behave or display on the content page.

References:

AEM documentation on Experience Fragments and Core Components explains the role of the Configure Dialog in setting component properties.

Guides on authoring in AEM highlight the different dialogs used for configuring components, including the Configure Dialog for detailed property settings.