Insert images in cli

I'm wondering, is there any way to include image files using the command line interface of joplin?

You use the attach command.

e.g. attach $n /home/user/pictures/unicorncatpicture.png

Great, thank you! Could it also work with images from the clipboard?

I don't think it does but if someone knows if that can be implemented then I'm sure PRs would be accepted for it.