One could argue that `class="m-0 md:m-4"` is more legible because it describes exactly what is happening. No margin on small screen, margin of 4 units on medium breakpoints. Where the styling on thumbnail is unknown and the breakpoints are unknown, unless you look at the css, then if you need to override that css you have to worry about specificity.
You're talking about CSS. I'm talking about classes.
> `class="m-0 md:m-4"` is more legible because it describes exactly what is happening
If by "what is happening" you mean "how it's styled", but that's extremely presumptuous. You might as well argue that there's no difference between Flash and an equivalently styled web page since if you took a screenshot of each they'd be visually identical—as if the whole thing begins and ends with getting the "rectangle full of little lights" to change in a particular way <https://xkcd.com/722/>. It's very narrowminded.
I'm not saying you have to be full on schema.org-conformant, but include something that actually makes sense instead of being as useless as the spew that CSS compilers put out.
