Yeah I wouldn't do this method tbh.
My friend tried photoshopping a sign to get a URL and endeded up gettign a call from Tumblrs lawyers and has a pending investigation on him at the moment.
But hey do whatever you please lmao.
In another case I've heard Tumblr requesting another image after the first one.
It's a lot of work for something that has the potential to backfire pretty badly.