Hi,
If the images there are checkboxes, it's just set the values in delivery metadata, read them in a control typology rule, compose the message from there. If they're inside a web control, you can have js copy them to the clipboard, then have marketers paste into the content. If they're intended to insert where the cursor is in the html editor, that isn't possible- use ootb personalization blocks for that, available in orange icon to the right of spellcheck.
Thanks,
-Jon