I’m not sure I’ve seen anyone successfully change the art content on their TV with an automation.
It seems like there’s a bunch of potential approaches for sending advanced commands to Samsung TVs, but none of them seem to be documented.
Of these, I suspect one of the more advanced commands like execute() or postOcfCommand() would be the most likely to support a unique feature like setting the image on the TV. Unfortunately, I haven’t seen any official documentation for those commands or support of automating advanced functionality from Samsung TVs.
And I haven’t personally seen much by way of the community (other than complaining of the lack of Art Mode control), but if you find something please be sure to update the thread!