One of the things I have liked about Mastodon is the encouragement to put alt-text on images. But as others have noticed, the more the network of mastodonians grows, the proportion of images with alt-text goes down.
It's not hard - please please PLEASE add alt-text to your images, even if it's just a quick note, and better if it's more descriptive.
@blainecross
Somewhere around here (it was last week some time) a user suggested adding explanatory text either in our own posts, or in a copy-paste-the-image style so that we gain control over the display of the image.
THis is one of those places where quote tweets could be helpful, fwiw