I'm a moron. Somehow I read "width" and deleted the irrelevant parameter because people have different screen sizes and the site should auto-detect instead of using my one.
Not necessarily worse density - variables are 1 byte names vs 2+ byte load instructions (often 3).
But the thing that gives JS a huge advantage here is the “standard (dweet) library” which has sin/cos/fill/line etc whereas x86 bios has “switch mode” and then it’s just a pixel array.
I think this one is more impressive for being in Javascript, which often has worse density than 16-bit x86 machine code.