The current drag & drop feature copies notes as a PDF file. (http://feedback.goodnotes.com/forums/191274-customer-suggestions-for-goodnotes/suggestions/19716046-export-individual-pages-using-drag-and-drop-mac-a)
However, It's sometimes desirable (and easier to view) if I copy them as images (to email app, iMessage, other note-taking app like Bear, etc.). I wish there is an option to select images over PDF.