Indeed, from what I gather from this thread and external links this “image” seems to be more of a plot than an image. In fact, are we looking at a matplotlib plot of the data with a “hot” colormap? The iopscience paper even references matplotlib. I’m just making some educated guesses here, but it’s still fun to think about. BTW: Python for the win! iopscience paper makes several references to Python tools (e.g., numpy, Jupyter etc.)
Another interesting thing about that iopscience paper is that you can turn MathJax on/off with a link at the top. Mathjax is off by default, but when you turn it on, you get a nicely rendered equation instead of a gif image.
