This is simple and perhaps obvious, but good for illustrating the simple WELLBY linear WELLBY concept, but that's already been explained above. I'm not sure what should maybe be put at the top. I'm not sure if it's useful down here. OK put this at the top, in a folding box -- it just helps to make sure we're all in on the same page about the definition of the WELLBY here.
Perhaps it would also be helpful to include some sort of adjusted WELLBY calculator interface that's a more sophisticated concept people might not appreciate, particularly embodying the approach in Benjamin and others.