An underrated accessibility feature on Lemmy is the ability to add alternative text to images in Markdown. The image above will be read as "photo of a snail" by screen-readers. The Markdown for that one is:
As you can see, the alternative text simply needs to be inserted between the two brackets, which are empty by default when you insert an image.
True, but the language is independent from that.
I mean, the language itself has a set of "features", not all of them are implemented on all platforms as you rightfully said, but it's not that the language changes because there are differences in the implementations.