Why was a bold, unrelated font chosen for formatted equations?

When reviewing my question, I realized that the body changes three times during the loading of the page (the screenshots below were taken as the page was loading, at various stages - there is a ~1 second delay between each of the formatting)

1. First the unformatted version is displayed

1. It then proceeds asynchronously to a first formatting (codename: NICE) to provide a nice visualization of the code

1. Finally, a new version of the formatted equation is displayed (codename: UGLY), where a boldface font replaces the previous one

The final font reminds me of Computer Modern but I am not sure.

Why does the ugly font replaces the nice one? (nice = similar to the other font, or at least which does not jump to the reader face)

Is this because of typesetting rules which cannot be enforced with the nice font?

• I don't not what you are referring to here. All looks the same to me. – amWhy Dec 3 at 21:11
• @amWhy: you mean you do not see the difference between the font of, say, 2.666666667 in the second and third screenshot? The first one is the font of the body (or close), the second one is a completely different one (maybe Computer Modern) – WoJ Dec 3 at 21:13
• However much your screenshots may vary, the linked Question does not exhibit this behavior when I look at it. One possibility is the choice of MathJax display method you've selected for Math.SE. Right-click on any math formatting there and you will see the second Item Math Settings has a submenu for Math Renderer. You might want to try various of these to see if the awkward type face is a consequence of some method that uses intermediate rendering for speed. – hardmath Dec 3 at 21:26
• @hardmath: the behaviour in the linked question is that these three states move from one to another. What you finally get is the third screenshot (I took the screenshots while the page was loading, at various phases of rendering). I tried your suggestion of fiddling with Math Renderer and I get the "nice" font (per my description) with Preview HTML(it was set by default to HTML-CSS). Thanks. – WoJ Dec 3 at 21:32
• I like the third one (that you refer to as ugly) much better than the second one (that you found nice). It's a matter of personal preference after all, isn't it? It's not bold btw, try \mathbf and you'll see how the font looks in bold. – Florian Dec 4 at 9:48
• I experience the behaviour of "font-jumping" as well. It is due to lag time which your browser takes when loading up the site. – YiFan Dec 6 at 0:45
• @YiFan: I believe that this is rather due to asynchronous calls, typical for web apps - the idea being that the whole page is loaded and then deferred activities are taking place which update the content.First the bare data is loaded (first screenshot: the LaTeX code), then a first rendering is done (second screenshot: the "HTML Preview" version in previous comments) and finally (third screenshot) the right CSS is applied (with the ugly font :)). – WoJ Dec 6 at 10:35
• @WoJ yes, perhaps so. I'm no expert on web design :) – YiFan Dec 6 at 10:50