So #EXIF (metadata for images and other media) defines fields for ImageDescription and UserComment (https://timestampcamera.net/photo-guides/exif-tag-reference), both of which could theoretically contain image Alt Text. I wonder if any social media apps (clients for Mastodon of other #ActivityPub or #ATProto services, for example) read and use Alt Text from EXIF on upload, or preserve the metadata in the file if you re-save it. Seems like a relatively obvious and useful feature.
#Accessibility #AltText