Empty blocks are placeholders in the layout of your Publish post. You can delete them one at a time, or turn off the guide that adds them.
How do I delete an empty block?
To delete an empty block from your Publish post, click it and press Delete on your keyboard. You can also right-click it and click Remove.
Why do I keep seeing empty blocks at the end of my post?
The empty blocks at the end of your post come from the Automatic Layout Guide. It guides you through building your post by adding placeholder blocks for your next photos. It's on until you turn it off.
To stop seeing these blocks, turn off the Automatic Layout Guide:
Open Preferences. Press ⌘, or choose Preferences… from the app menu in the menu bar.
Go to the General tab.
Under Layout, uncheck Automatic Layout Guide.
Publish stops adding placeholder blocks for your next photos.

