Reposting this with alt text. In fact the entire description is in the alt text.
@Bunninsula On Mastodon it's also known as an "image description." It's text describing an image so that people who are visually impaired can understand what the image is. When visually impaired people use Mastodon, their computers read the text out to them. Usually it's not visible until you tap on the image or hover your mouse over it.
You have the opportunity to add this text when you add an image to a post.
There are a lot of blind Mastodon users and they really appreciate alt text.