[hunter2_]

Ding ding ding. As a sender, the upside is that virtually all GUI users will see the images without prompts or placeholders; the downside is that you don't get a read receipt. As a (GUI user) recipient, the upside is that you will see the images without prompts or placeholders while preserving your privacy; the downside is that you hit your storage quota way sooner.

Technically, embedded images are a lot like attachments, but mail clients are smart enough not to display the little has-attachment paper clip download widget because the MIME headers for the image will say "Content-disposition: inline" instead of "Content-disposition: attachment". Then the HTML img element references it using the cid: scheme instead of the https: scheme or similar. Anyway, the experience is great.

I suspect Mail Studio doesn't offer this because its MO is that "Designs are exported as standard HTML and can be imported in your email marketing platform of choice." This embedded image technique would require that Mail Studio export (or send) the entire multipart MIME message, not just the HTML part.