Test to make sure that the editor and the front match. To test the Stack on mobile setting, reduce the browser window width.

The control these settings, the block uses the css classes "has-media-on-the-right" and "is-stacked-on-mobile".

The separator has three styles: default, wide line, and dots.

The spacer block has a default height of 100 pixels:

And finally, the page break:

This paragraph block is on page two, after the page break.