Trying this out now. Interesting idea! It sure does load slow on 75,000+ reblogs. Also, I wasn't quite sure how it worked when I clicked (didn't realize it showed up below the post) and clicked it twice. It's loading the graph twice. Maybe make a second attempt on the same post not load another copy of the graph?

I wish there was metadata about individual nodes or the structure. I would also like links to the nodes to find tumblr blogs that get a lot of reblogs.