As part of the broader discussion around the post content block removal warning #52392, the post content block placeholder came up as something to improve to help address the problem of folks removing this block without understanding the impact. This ties into an effort a few years ago around block previews and placeholders for site editor blocks #30029.

Pulling from the feedback in the post content block removal issue:

Add more visual distinction to the Content Block to indicate that it is a special block. this could be done by:

• Using a special accent color, similar to how Template Parts and Patterns have a purple border and purple icons. Dynamic blocks like Content, Featured Image, Query Loop and Post Template Blocks could have the same accent color to distinguish them from “regular” blocks.
• Add other visual cues like different background color/border or placeholder iconography to indicate that is a placeholder/dynamic block, similar to how the Featured Image block has a crossed-out grey background
• Make the text inside the placeholder not selectable with a text cursor, so that it's clearer that is it not editable. This also applies to the Title Block. (h/t @supernovia)
• If a user tries to highlight, delete, or type over the placeholder text, a modal can pop up with instructions on how to edit that section for individual posts/pages/CPTs. This also applies to the Title Block. (h/t @supernovia)

Curious what else folks have in mind and what we can do to continue to iterate cc @WordPress/gutenberg-design