One of the impressive things about the Steemit is how they handle the plagiarism and duplicate content.
Ther are no filters that can stop you doing this, or pasting images and the videos.
IN fact, posting the videos from the Youtube is allowed as the Steemit provides a script and even some notable members made tutorials how to include youtube videos in your content.
Images are pretty much easy to paste because the uploader is directly provided with the text editor, so we are able either to upload free images or our own.
Your own will always be accepted better and without a doubt, duplicates from another website will not attract any valuable upvotes, so you won’t be able to earn with the wallpapers and similar things.
For what I have found, only funny memes made notable earnings, but it is only a few dollars for one article.
The plagiarism is fought by an entire community, as we are able to flag the duplicate content and fight off spam in that way.