Documentation
Components and instances
Making a reusable component from a selection, placing instances and overriding them.
Select one or more layers and create a component from them. The definition lives on the document; every place it is used is an instance that follows it.
Overrides
An instance can override a text, an image source, a label and a style patch on any node inside it. The vocabulary is deliberately smaller than a whole node: an instance that could change anything would be a copy.
Detaching
Detaching an instance turns it into ordinary elements on the slide. It no longer follows the definition, and it cannot be reattached.
Containers and layout
A container with a layout lays its children out in flow: an in-flow child has no left or top and the width shown in the Inspector is the width drawn. Everything else is absolutely positioned. Removing the layout puts a child back where it was, because its coordinates were never discarded.