@PinkElephant There's two ways to display text as code in EN—one is with an inline code snippet which is created by surrounding text in backticks, e.g. `The != symbol will now become ≠ in this code snippet` and (2) code blocks, which you can shortcut with three backticks ``` (your bottom screenshot). In code blocks, the mentioned symbols don't become glyphs, but in code snippets they do.
Maybe other people use this feature for something other than code, but that's what I've always assumed they are for.