The interactive carousel uses HTML and JS, hence it can be used in any blog (internal & external), but cannot be directly embedded into emails. We have a separate embed code for embedding products into emails - this will display products in a row and will not have a dynamic behavior like left/right arrows.
Ensure that the widget is 'E-mail enabled' and click on the In Email window to generate the HTML code. You can choose the number of rows and the number of products per row.