entity_embed_placeholder

This module will render a custom display to use as a placeholder or preview while editing a piece of content on CKEditor.
By default, Entity Embed doesn't provide a mechanism for previewing or providing a custom display mode of embedded entities while editing content, instead it renders the entity as it's displayed in the frontend, which in many cases it's an issue.

See https://www.drupal.org/project/entity_embed/issues/2882866

Features

This module provides an alternate rendering for nodes and media entities through a custom template and library. Use this module if you need to have a preview or placeholder of embed entities while editing content.

Post-Installation

After installing this module, entities embed on CKEditor will display the entity title and type, in the form of a placeholder.
You can customize the look and feel in several ways, see the project README for documentation, the templates have the same variables available as the base entity templates, so you can include as much data as you need.

Additional Requirements

Entity Embed module.