All custom blocks should have a block preview
Introduction
Include a preview for all custom native and ACF blocks so that when you hover over the block in the block inserter, a preview is displayed.
Decision
Block previews are needed for custom blocks. The preview can be generated by passing your block's attribute values or by using an image as the block preview.
Context
A preview for a block helps editors see what the block will look like before they insert it into a post.
Consequences
- Adding a preview can require additional work and extra steps.
Exceptions
- Older blocks: You don’t have to add previews to existing blocks.